Legal mining companies and people are paying for the electricity energy their miners are consuming, the power supply is not for free, even many people working in electricity company are even happy because the more the miners, the more the electricity usage, while the more the money that will be generated. You can not compare electricity generated in a village to the ones generated in a well developed city, the more light generated in advanced country like China, the more people will be employed in electricity companies. PoW really helped.

And as for centralization, ethereum 2.0 PoS will be more centralized than using PoW as anybody not having 32 ETH will not be included in the mining aspect.