who can use a daily currency that is taxed for capital gains on every spend.
That question makes no sense to me as a U.S. tax payer. Given a choice between holding my spending money in a form which loses value costs me much more than does holding it in a form which gains value, regardless of whether the gains are taxed.
1. The hassle of recording and paying tax for numerous daily tidbit transactions is far outweighed by the insignificant value loss of holding $500 in your checking account (exhibit my prior post that average Dogecoin holding is claimed to be $430 per user).
There is no hassle, because it is trivial to automate. A pretty large set of users just don't file tax returns, and could not care in the least. Another large set have people who do that for them. The remainder generally have an app for that.
Bitcoin has enormous usability problems for quotidian consumer applications. I am acutely aware of this. But capital gains tax is not one of them.