How do low-transaction fee coins work: if they don't have much volume and have low fees, how do the miners/validators get any appreciable reward?

I'm not speaking about BTC/ETH or even like ADA/Uniswap. I'm speaking about random coins similar to tectum.io that aren't within the prime 50 or 100. When you have a coin with low transaction charges, where do the rewards for stakers/miners come from? Plenty of PoS networks pay 6-12% APY for validators, but when they don't have much in phrases fees claimed, the place is that this coming from (usually)? Is it just because additionally they have so few validators so it's a small pie but few on the desk type of factor? I really feel like there's a better answer but I'm unsure what it is.