Yeah there are people that make a living (or try to) collecting satoshis out of those things.
Absolute waste of time. I don't believe there's one person who is seriously making a living out of solving captchas and reading texts.
I will add that I don't think that trying to earn from faucets worth the money one would spend on electricity for the device he will use for browsing there.
Let alone the energy and time he spends himself...
They can be useful for testing sending a few satoshis between wallets or for other experimental purposes
Nope, neither for that. For experimenting we have the testnet.