So I'm new to this. I learned %51 attack is possible but not likely because whole ecosystem is affected and pool owners don't want that.
I checked https://btc.com/stats/pool and I see 2 pools have more than %50 power. Isn't it bad for ecosystem? Why do miners stay in 2 big pools and give them more than %50 power? Even if they don't use it for evil.

Foundry USA: %27.2
Antpool: %24.5

Wouldn't it be better if total of the biggest pools are less than %50? Would you prefer 4 pools for %50 rather than 2 pools for %50?