Well, this one is pretty recent, and is growing pretty large: The World's Newest Major Religion: No Religion
I think that one of the newest trends in religion is do-it-yourself religious eclecticism. It's very common here in California, where it's almost the state religion. We see it in 'New Age' bookstores with shelves devoted to every historical tradition that one can imagine, often the more heterodox, underground and 'occult' currents. People take what they like from here, something more from there, and then form their own personal mix of ideas. I think that the appearance of the internet has accelerated it dramatically. No matter where we are, every religious tradition on earth (and 16 other planets) is just a few finger-taps away. So everyone who is interested is getting exposed to everything. I don't think that I'd call this kind of religious eclecticism 'start-up' religion, since it's hugely individualistic and each variant is often limited to the individual who thought it up and likes it. The 19th century appearance of the LDS church was more of a Silicon-valley style religious start-up. Or to take a far less organized example, perhaps the very widespread belief in flying saucers. Or Marxism.
On freshman orientation forms, one of the questions was "Church preference." Word circulated through the hall, and nearly everyone wrote, "Gothic cathedrals."
Even as a religious person myself, at one point I expected less religiosity to be a good thing overall, since religion on the whole has done more harm than good. What I've come to see instead is that when people lack religion, they will seek a surrogate en masse and the effect that these surrogates have on thought and behavior are, at best, exactly the same and, at worst, potentially even more terrifying.
Good example. A successful new religion that was also a money-making scam for the founder, and seems to be in decline. On the other hand, this illustrates difference in approach to state meddling in religion between Malaysia and the US. L. Ron was not even indicted for conspiracy when his own wife (high ranking Scientology official herself, sort of head of enforcer's wing, ghm, sorry, "Guardian's Office") was. It may seem frustrating at times, but US approach is better.
Welcome to Jediism, and may the stuff be with you. https://www.theguardian.com/world/2020/feb/11/you-have-to-face-the-darkness-within-you-meet-the-real-life-jedi-knights?utm_source=digg