Just like everything it depends on what you buy and when you buy and sell it. Post 2017 the largest theoretical gain from bitcoin so far was about 20x, if you bought at the post 2017 low in December of 2018 and sold at the 2021 high almost three years later. Gamestop stock almost matched that 20x for 2020-21 gains alone. Apple has been up well over 500x in the last 20 years.

Ethereum was a better deal during this time, but you'd have to know to buy it. And some people really made bank on altcoins, but again, right time to buy, right time to sell.

There's a limit on how much the crypto market can be worth with people still able to use it as a currency to buy things. Logarithmically we're closer to the top than to the original bottom, though like all markets timing can still yield very good returns, especially if everyone else is hodling like Fort Knox.