This. Theoretically any asset can go to zero. Gold can go to zero. Bitcoin can go to zero. Apple can go to zero.

Practically though, Gold and Bitcoin will likely only ever increase in price. Any company, Apple for example at $3 trillion, is much more likely to go to zero than Bitcoin, because its a business and it could always lose its competitive advantage. Bitcoin is a perfectly hard currency so it is very unlikely anything in the future could ever overcome its lead in globally strong network effects. And since it is perfectly hard supply capped the best anything could do in that regard is simply be equally as good (I wouldn't say an actual deflationary currency would be better because the end game for that kind of currency is that it literally doesn't exist anymore!). So practically let's say it has a 0.00000000000000000000000000000000001% chance of going to zero, and a 99.999999....% chance of going up for the very very long term. The only thing I'd put at a smaller chance of going to zero is Gold, because its got thousands of years of history behind it and is also used for in electronics and aesthetics.