Most of the time gimmicks. Some of them give out legit rewards, but more often than not the value you get is really low. It's probably due to how easy it is to make the coin itself and with a bit of know-how, you can create a "business" look-a-like model that you can show to people so that you can scam the money out of them. I'd honestly not recommend any beer money-like schemes in crypto itself, you'd probably just waste your time.

Look outside of crypto instead and use the money you earn to invest. It can be doing survey questionnaires, a 2nd job, or a part-time. Look for something that can suit your time. Best choice here related to crypto would be signature campaigns but that requires more time than what I initially recommended (due to merit requirements).