1. You pay for it in cash
2. It's "free" but you pay for it with your data which is harvested and used to target ads at you
3. The weird Brave crypto model which basically does what 2 does, but you get some token for it
4. The Firefox sell your search traffic to Google model
Number 1 gets completely blown out by 2 when they compete in the market to the point it doesn't exist anymore, so that's not really viable. 3 seems scammy and nobody really wants it anyway. 4 is what I use, but let's face it, it's just 2 light with better ad blocking. It's also probably on its last legs since the courts have ruled that Google can't buy default search (which ironically will probably enhance its monopoly position).