It's greed.
The people with a fuck load of capital want to crave themselves out a large slice of the pie, so they can earn more than the next farm. But it is a vicious cycle, the more gpu's added the more you need to add to stay competitive and then electricity slowly eats away at the profit. That is when a coin goes sideways instead of pumping.
It screws the small miners and gamers AND it screws AMD long term in the gaming market. Gamers want a card can't buy AMD and see it is priced high so they go with Nvidia which shrinks their gaming market that they earn the most from.
Well that's just how the mining game works.
Welcome to Capitalism.
Its not only mining where its like that. Where there is easy money to be made, others pounce as fast as they can. Nobody wants to do manual labour anymore or work for minimum wage.
For example,
Look at the entire E-Cigarette/Vap market. A few years ago there were no stores and now there is a store on every corner selling them since the demand is crazy high and they got huge mark-up and the owners are making crazy profits.