I have noticed that the 2nd job has a budget of 15 ETH and the 3rd one has budget of 2 ETH. How could we know the one who needs those jobs to be done will pay us. workingforbitcoins.com seems like a freelancing platform to me, if I'm not wrong then they won't be paying us. So who is going to pay us?

I'm willing to do those jobs as I'm quite good at excel and I can write quite good crypto content but I don't think that I will get paid if I complete the jobs, however I'm willing to take risk and apply for those jobs and see if I get paid or not.