Many of them are marketplaces for freelancers. While some are like task type websites. As long as they're legit, test them if they really pay.
But be careful also with random and unknown platforms that asks money to deposit because that's already a red flag that you should remember.
Anyway, I hope that OP will still update the list and adds more that are genuine.
Yes you are correct , we must be ready for risk and we should learn how to manage our expectations .
There are scam websites that are also doing the same tactics like the typical scams that will ask the freelancers to ask for an amount to get deposited for them to "promise" their employment.
Not only websites but likely scam employers. So, it happens on many platforms so please be mindful on that and if you're an aspiring freelancer and they're asking you to have some deposits, never oblige yourself to follow that instruction.
Don't get blinded by simple red flags for your own sake.