The funny thing about this is that the phenomenon being pointed to is not actually real, yet the data itself -does- point to another, far more interesting phenomenon.
You see, Buddhism in the United States is unique, I have often said to my chagrin that "Buddhism is not real", this is true. Buddhism is not real.
Buddhism is an ontological framework without epistemology. This may be confusing if you've -only- ever interacted with Buddhism from a Buddhist epistemological framework, but once inside you see that the epistemology is itself the raft that the Buddha himself speaks about that must be discarded. Buddhism's foray into America was unique because it infiltrated through a specific vector in three separate waves.
The first wave was the Theosophists like Blavatsky who brought over Theravada the second were the Neo-Theosophists like DT Suzuki who brought over Chan. What you notice in both Theravada and Chan is that they're not 'Buddhism', both love to claim authenticity, and both are authentic, but neither one nor the other is uniquely true Buddhism. Theravada's Pali textual canon -isn't the oldest- despite that claim being repeated as a sectarian myth over and over. Likewise, we have no proof that the original teachings of the Buddha were Mahayana either. The final wave was of course through Tibet and Taiwan, via the Communist regime's illegal annexation of both and subsequent genocide of the former.
Despite this all, we do have a clue in the concept of upaya, which is where we get the idea of the raft in the first place, skillful means, the idea that epistemology is merely a vessel to ferry you to an understanding of ontology. When you reach that state, the epistemology is abandoned. This is Buddhism's central epistemology, it is self defeating, self burning, self immolatory. You might be inclined to then say, well then how come Buddhism maintained such a coherent ontological presence over 2400 years. The answer to this is simple, because back then Buddhism represented the spiritual arm of Empires. The Chan Buddhists courted favors with the Chinese emperors, the Tibetans embedded themselves into the framework of Mongol and Tatar Khans. The Theravada became the epistemological framework for the Kingdoms of Sri Lankha and Thailand. In all of these situations the continuity of Buddhism was propelled, entirely, by a monastic system propped up and supported by dynastic rulers. There is no such thing in America.
What happened with Buddhism in America was the epistemology was simply a bunch of fingers pointing at the moon. There was no Japanese Emperor to maintain a tradition of Zen. There was no Thai King to maintain a tradition of Theravada. There was no Dalai Lama as the King, there was no Chinese Emperor. What you found was a nation of Spiritualists and the Post-Religious, a people who had lived through not one Reformation but FIVE. The Reformation, the Radicalization (that led to them coming to America), the Great Awakening, New Thought and Spiritualism, and finally New Age. Arugably six if you count Post-Modernism.
So what happened? Well Americans received all of these texts along with everything else from Gnosticism to the Dead Sea Scrolls and all of Hinduism and Daoism and Bahaism and everything. We received everything all at once. Some Buddhist missions came, and people might have called themselves Buddhists for a time. Yet the idea that Buddhism was not a religion went further, and in a way, it isn't, if a religion needs institutional power to be a religion, then Buddhism in America specifically is not. I have gone to many Buddhist temples, do you know how many people consider themselves Buddhists there? Not many. Yet these institutions keep growing, not closing down. Buddhist temples take over abandoned Churches throughout the decaying Midwest, why is that if Buddhism is declining?
The official Buddhist numbers are immigrants. The Tibetans and Chinese who came here en masse fleeing persecution, their children are Americans, they become American Buddhist, which means they are agnostic, atheist, a 'non', or just 'spiritual', and so they don't consider it their 'religion' because they don't have a religious relationship with Buddhism like their parents or grandparents might have.
This would be a good enough argument alone, but there is also something else happening that I gestured to at the start. Buddhism is an ontological belief system, not an epistemological one. I have recommended the book "The Secular Paradox" many times because it points to a trend that is rather unintuitive for many common people, the idea that society is becoming less atheistic and less materialistic, that people are becoming more religious and more spiritualist, they're just doing it in ways that are eclectic, secular, and hard to quantify through census visualization.
In the year 2026 people all over the country are doing yoga, meditation, the belief in reincarnation is almost universal, the Buddha is as recognizable of a figure as Jesus and many people, especially secular more affluent ones, find more 'inspiration' in him than even their own Jesus. Our entire therapeutic system that propagates psychotherapy like DBT is built upon a secularization of core Buddhist tenets, and this isn't coincidental, this is something you can simply read about, all of these things are deeply interwoven. Bay Area tech people ushering in the 3rd Industrial Revolution are doing 'Jhanas' and independently having experiences that they describe as Non-Duality, the eschatology of the Yudowsky's Witnesses is eerily similar to the industrial age Buddhists of China who foresaw the coming age of Maitreya. People are collecting in groups, creating sanghas, in the congregational manner, they are having "vibe" camps and discussing panpsychism. People are making entire careers teaching 'tantra' to people and calling it 'spells' and 'manifestation', they're reskinned the entire tantric playbook as 'witchcraft' and your little sister scrolling tiktok looking into tantric magic of another name is none the wiser. Don't even get me started on metta. Even the psychadelic stuff and how it is framed and used as therapy and how it all maps 1:1 onto Buddhist phenomenology.
Buddhism's ontological claims infected the affluent American's mind so thoroughly that almost none of the aforementioned folk and their extended circles would answer on a religious census that their 'Religion' was Buddhist, most would likely be openly hostile to the framing as Buddhism as anything more than a philosophy. Yet all of these people are Buddhists and are actively participating in the epistemological formation of a new form of American Buddhism that has its roots in the New Age and ultimately upwards in the genealogy to Congregational Calvinism.
America is a secular nation, it is a pluralistic nation, we are religious about our civic religion which is non-religious in a religious way. Buddhism's degrowth represents an adoption of her core claims into the affluent ruling class and the assimilation of the Buddhist refugees into this 'New Buddhism'. Buddhism isn't dying by any stretch of the imagination, but the epistemology laid out by Shakyamuni Gotama is, and that is a time of rejoicing, the prophecies of old all speak in unison, when the Cowherd's epistemology starts to unravel then would be the age of Maitreya and a new golden age will come.
Now is the age of Maitreya, the Dharma ending age is passing before us. Now is the time for celebration.