I would say scarcity is a small part of the equation, it's about demand for the float, in bitcoin you see miners only selling when they have to, they want to hold on to the value they created long term as it can increase their profits, so a fraction of the coins are brought online to exchanges each day along with traders buying and selling. But there's always a constant demand for the supply as hodlers take it off the market.

Now with these other coins, they don't have that, all the central issuers want to dump their coin, they see no reason to keep it, so to account for the lack of buyers, they come up with all sorts of gimmicks like staking rewards, lock-up periods and a bunch of other penalties

Look at BNB they're constantly issuing and burning their token, it's almost like on-chain wash trading, contracting and expanding the supply because they've hit peak demand for their shitcoin.