How does it prevent competition? Nothing is stopping you from buying more CPUs to mine or finding more competitive sources of energy.

The difference is this way it is more accessible to plebs vs ASICs.

It's more hidden too: ASICs are loud, hot, and draw a lot of energy. It's super obvious to everyone why you are buying that ASIC. You stick out like a red target for criminals and governments.

"Police raid a concealed #Bitcoin mining operation, initially mistaking it for an illegal marijuana farm due to the heat signature"