until now im just only know 2 way for earn crypto without invest and mining, the 2 way itself was through bounty and airdrop, but mostly program now neither bounty or airdrop was fake and scam.
those 2 are worth to do as long as there are no KYC to do.
You are not investing any amount of money though your time and effort.
But i will tell, bounty hunting is really fun and nice to do.