Look at where hold 'em is now. It still exists, of course, but you don't see poker tournaments broadcast live on ESPN anymore. It's not even a very popular livestreaming category. It definitely went through a boom, then huge bust, and then a slide into... not really irrelevancy, just kind of a continued existence.
IMO, crypto is headed for the same fate. It will still be fun for a subset of people to gamble on altcoins, to pump and dump and run schemes of dubious legality. And just like I wouldn't count out a poker resurgence sometime in the next decade, I wouldn't count out another crypto spike in the future. People never stop loving easy money.
People may be underestimating how popular hold em was in the mid-2000s. As another comment in this thread said, it was even more popular than crypto is now, and that's without the extensive use of social media that we have today.
Which relatively quickly died off.
Casinos. Seriously [1].
[1] https://pubs.aeaweb.org/doi/pdfplus/10.1257/jep.13.3.173