OP, you are so wrong, these aren't just platforms were you earn money by performing tasks. These are freelancing platforms where companies and other employers outsource their projects to qualified professionals, and they do this from the economic point of view, possibly to cut down the cost of employing and maintaining an in-house professional. You don't just do tasks, you bid for these contracts, the employer verifies your capability and outsources the contract to the most qualified professional under some agreed upon terms which includes project cost and payment schedules based on milestones or at the end of the project, depending on the agreement.
Its in no way tasks, you give tasks to someone already working for you, but contract is for someone whom you want to work for you for a specified length of time.
You're right, these are platform you will register with, build a profile and deliver a service to potential clients and they get paid and pay you back for the service offered, though i like the fact that they are sites some of them were of high reputable standard and am also used to few among them, it's a big avenue for those looking for a social media platforms means to earn or generate income, henceforth people should know that nothing goes in for free in this world, you work and you earn as you do so, i think these are more interesting than cloud mining, faucet or survey and all forms of airdrops and NFTs.