Just want to bring up the facts that:

A) NFTs were a thing long before the 2021 pfp craze (who remembers crypto kitties?)

B) Memecoins were a thing before even Ethereum existed (aka doge).

And yet the craze for both of these happened much much later.

What is out there now that will have its craze 3 years from now?

It's true, trends in the crypto world can shift quickly. It will be interesting to see what new innovations will capture everyone's attention in the next few years. Exciting times ahead!