relative really. I can't see it ever being really big unless some major celebrity started trumpeting their love of the hobby. reality is it is very time intensive and can be very expensive. most people don't think about plants when they go on a cruise or something. also, very few will have the patience. I could see it becoming a small cash cow for a small group of yamadori collectors. I could see the potential for reckless collecting with people paying the amounts they are for the material. it was rampant in Japan but the US is ridiculously bigger.
Actually those are really good points.
I can see it growing for a few more decades, then plateauing. Possibly a big boom inside the next decade as all the people who jumped on it during quarantine finally become proficient and begin teaching friends and neighbors. Then, as
@penumbra said, a stead drop as the fad subsides, eventually leveling out to the point where everyone knows someone who does bonsai, and 1 in 10 have played with the idea.
But what really caught me was your statement on reckless collecting.
In preparation for an upcoming collecting trip, I stopped by the local USDA Forest Service office to ask about permits. They were out, none to be had until May at least. Why? Someone came in and bought up 4000 personal use permits in one transaction at $10 a piece. I'll spare you my monologue on the corrupt nature of of such practices, but if nothing else, from a US business standpoint at least, it would inevitably become dominated by a fistful of companies that don't mind tearing apart the very thing bonsai is meant to connect us to in the race for a fast nickel.
I can't imagine the likes of folks on this forum standing for it, and I can imagine activists who know nothing about bonsai trying to abolish it seeking to combat the very same thing we are.
Unfortunately, for bonsai to thrive in modern American society, it has to grow slowly.
That or, ya know, we kick some political ass until DC gets it's head out of its ass.
I'm all for option #2