Somethings I remember generating a lot of excitement at first.
Mining, when it could still be done with graphics cards and early mining machines.
Gambling, the early sites SatoshiDice and later Just-Dice had huge followings. Looks like there is still a lot of crypto gambling just split up over many more sites now.
The early Altcoins such as Dogecoin and Huntercoin.
Tokens and Dapps made possible with Ethereum.
Earlier Tokens with the airdrops were very profitable.
Dapps looked very promising at first, not sure they've lived up to it yet.
What do you think is next?
You must have known Bitcoin very early because what you mentioned is very interesting. Bitcoin and Altcoins will adapt and develop in a different stage each. I'm feeling 2020 is a return season for Bitcoin and a season for Altcoins so whether you earn Bitcoin or Altcoins by different methods they are very useful.
about thinking in Bitcoin or crypto the next is likely to be in fundrasing again,
because from 2017-2020 there are many variations of fundraising,
from ICO, STO, IDO, even IEO in 2020 to be popular, 2021 may have new things again.