donating online

Yeah i suppose any form of payment that you have to keep secret for some reason is a reason to use crypto, though I struggle to imagine needing that if you’re not doing something dodgy

avoiding scams for p2p transactions

Wat. Crypto is not good at solving that, it’s in fact much much worse than traditional payment methods. There’s a reason scammers always want to be paid in crypto

boycotting the banking system

What specifically are you boycotting? The money that backs your crypto (i.e. that you bought it with) still sits in a bank account somewhere and continues to support the banks. All you’re boycotting then are payments, but those are usually free for consumers (many banks lose money on them) so you’re not exactly “sticking it to the man” by not using them. Evem if you were somehow hurting banks by using crypto, if you think the people that benefit from you using crypto (crypto exchange owners and billionaires that own crypto etc.) are less evil than goverment regulated banks, you’re deluded.

What about avoiding international payment fees?

You’ll spend more money using crypto for that, not less