The miners just like most of us now, just interact with some apps, do the task required by the devs and claim free coins daily ontill the project lunches, then sell off and enjoy the money. You pay nothing to get them, every free money in crypto is called AIRDROP.
You are getting it wrong OP...
Claiming an Airdrop doesn't make you a miner it'smore like giveaway token to your wallet...
Minning is totally different from what you just said fine you can mine using your phone maybe for altcoins but using Bitcoin as an example you need to have a high computational power to mine coins , although years back you could mine with a low power since the hash wasn't high then but now there's a need of dedicated hardware like Asics which are now use in the process.
Altcoins might not need specific hardware but some does so far it uses the POW (Proof Of Work ) system, some Uses the POS( Proof of Stake)....POW is quite different from POS mechanism you can DYOR about that as not to go off topic