I will choose to use legal currency as a reward. Although many countries have legalized Bitcoin,
Not that many actually but they're more than those that have declared illegal on it.
I think it is better to use legal currency to buy coins that I like. Fiat is more often used daily.
You are just adding some process if you'll just about to buy cryptos with fiat. Then just accept crypto directly and then just trade it on exchanges if the purpose is to trade.