Who in their right mind would waste their Bitcoin on taxes or buying random stuff?
Who in their right mind would waste their Bitcoin on taxes or buying random stuff?

Can't comment on taxes because it's different in every country and depends on individual how they manage it.
Who would use their bitcoin for payments?

Holds only bitcoin and no fiat
Not interested to see few things in bank/card statement
Merchant accepts only bitcoin or other cryptocurrencies
Want to avoid payments being censored by governments

Also using bitcoin for payments allows you to buy more things over a long period of time especially bull markets:
https://link.medium.com/p8oVGwGWAgb
Normally people manage fiat in bank account, credit card, long term savings, investments etc. If someone wants to buy ice cream, most probably they will use cash/card and not withdraw money invested in markets or long term savings. Similarly, bitcoin can be managed in cold storage (long term savings), hot wallet on-chain (for payments, trading, etc.) and LN wallet(for quick payments with low fees). Don't need to use cold storage for payments.