El Salvador abandons Bitcoin as legal tender

Do pro-bitcoin people still talk about goals of bitcoin being a currency that people use daily?

I don't follow it closely, but that idea seems to have faded and now it's just an asset to buy and hold while it magically goes up forever.

It doesn't have to be "magic" that causes it to go up forever. People need a way to put large amounts of money in places that are difficult for governments to get to and /or easy to move across jurisdictional borders. Think: money launderers, people that are worried their corrupt government will seize their assets, people hiding money from someone they owe like a spouse in a divorce. These all seem to me to be reasonable use cases for bitcoin.

All the things that make bitcoin a pain to buy a pizza are irrelevant if your goal is to hide $100m in your shoe. Nothing can do that better than bitcoin and there is a demonstrated need.

If you assume the reason to use bitcoin isn't going away and the wealth of the world goes up-- while the supply of bitcoin is pretty constant-- it can keep going up without magic.

But that doesn't distinguish Bitcoin from other cryptocurrencies. The thing that distinguishes Bitcoin is fame, pure and simple. Everyone has heard of it.

Also nobody can premine it, no coalition of big stakeholders can lock you out of your coins, a 51% attack is less likely feasible than for any other PoW coin, the bandwidth needed for its blockchain is smaller than most alternatives, and it's less likely to conceal unknown cryptographic weaknesses. It's kind of shitty in some other ways, though.

And eventually the math will be solved and every bitcoin will be worth zero.

While that's conceivable, Merkle-graph systems like Bitcoin are surprisingly resilient. It's been almost 20 years since MD5 was thoroughly broken, but still nobody has published a second preimage attack. For SHA2 and SHA3 nobody has even published a collision attack. And SHA-256 (what Bitcoin uses) is post-quantum-safe (Grover's algorithm still needs 2¹²⁸ time) though AFAIK there isn't yet a post-quantum cryptosystem deployed for signing transactions, which will require a hard fork.

Presumably if quantum computers (or better DLP algorithms on classical computers) start breaking keys, that will become a priority.

So I think there's an excellent chance that even if the math is solved Bitcoins will retain their value. Perhaps even without many of them getting stolen in the process. This is a big difference from many other uses of cryptography; if someone breaks IDEA 20 years from now, they can decrypt your PGP messages from the 20th century, and there's nothing you can do now to prevent that.