In 20 years, people will either be saying Remember when you could buy bitcoin for only 3500? or Remember when everyone lost their minds and spent millions on useless internet money?
One day cryptos might boom in such a way that basically everyone who didn't invest in them will become poor
If we take into account that it is almost impossible for anyone to predict what the price is going to do during the next day then it is quite problematic to try to predict what it is going to happen in such a long time frame, however since I really believe that cryptocurrencies are going to become successful since countries around the world seem incapable of stopping printing money like crazy then your first scenario is more likely.
But in 100 years I really think that bitcoin is going to be in the history books and the same will be true for the mysterious person that created bitcoin and even after so much time I think they will still try to identify who was the person behind the name of satoshi.