As long as you live in a country you will be taxed. That tax will be charged in fiat. It would be great if you pay it in crypto, and maybe third parties will pop up, but I can't see governments letting that go.

And also in many areas more than 50% of the population is dependent on government money, either public sector jobs or welfare of some sort. That money is always going to be paid out in fiat.

I could easily switch to pure crypto right now. All I'd need is places accepting it. But I would not not leave behind a proper bank account and switch to a crypto debit card for the moments I needed that. None of them are competent or dependable enough.