I think both have their place. I think it is interesting that you claim that more goldcan be found, yet not more bitcoin can be made. That's a false equivalency. Gold never was, and will never be the only source of currency. Other metals can be used, like silver, like copper... Other materials can also be used as currency.

For cryptocurrency, you are right that there will never be more than 21 million bitcoin, but there's no end to the total amount of cryptocurrency. Even if in say 200 years only cryptocurrency would still hold any monetary value, you might still have the case where those 21000000 bitcoin will buy you 1 single loaf of bread, and one of the thousand of other crypto's which already exist, or of the thousands more which will be made by than will be considered much more valuable, and your current investment in bitcoin is pointless.

Best to diversify between different crypto's if you believe that crypto will continue to keep booming.