There was no way for staking rewards on Ethereum to compound till now because there was no way for any staker to withdraw their CL and EL rewards.

Now they can.

And restake it.

PoW miners have a lot of operational costs to cover with the block rewards and tx fee that they get, which will keep increasing with increasing difficulty.

The only direction for the difficulty target number has been down and nothing else.

Which means difficulty of mining has kept increasing over the years.

Hence, the cost of mining has kept going up. Bitcoin had to be sold and supply had to be redistributed.

There is no such thing for stakers.

There is a one-time cost of setting up a staking node and buying 32 ETH.

There is no real necessity for them to distribute their rewards into the market.

Possible centralisation vector for PoS block production and validation.

And we'll be able to see what happens at a proper scale with a network as big as Ethereum having implemented it in full with the shapella upgrade. It has been incomplete till now. No more speculation.

If you want to keep an eye on what happens, there'll be data on dune analytics.