[nlitened]

> In this scenario, would one's rate be set in BTC, or fiat?

You set the rate in USD, and do the currency conversion upon sending.

> I'm struggling to understand how a (non-crypto) business could want to hire a contractor at - let's say - 0.016 BTC/day

You’re right, BTC is too volatile to set the price in it in advance. But it is a perfectly good payment method.

It’s true that if you need the money you receive in BTC to feed your family tomorrow or they starve, then BTC is not convenient and too risky due to price fluctuations. But if you’re a reasonably compensated professional or a business with healthy margins, there’s very little downside in receiving 10—20% of money as crypto, and potentially very high upside.