If you want more details you can always read the Gasper paper[1], the spec[2], or client code.
It is complex to somebody not familiar with consensus and blockchain execution, but you might say that about any modern engineering. PoW is undoubtedly simpler but also exponentially more environmentally destructive.
I personally find the ESG argument to be a misnomer. You're trading security and a well defined execution layer, for a significant amount of complexity. If you want to moralize energy use, then you have to apply it at all levels, not just call PoW bad for the environment.
It is complex to somebody not familiar with consensus and blockchain execution, but you might say that about any modern engineering. PoW is undoubtedly simpler but also exponentially more environmentally destructive.
[1] https://arxiv.org/abs/2003.03052
[2] https://github.com/ethereum/consensus-specs/blob/dev/specs/p...