Aside from whether PoS is better than PoW in terms of environmental, security or decentralization, the fact is Bitcoin community most likely won't agree with big changes.
Even block size increase, SegWit and LN which are "less controversial" have hard time accepted by the community.
Additionally, by moving to PoS, Bitcoin production rate & total supply are forced to changed to make PoS works, which are also controversial topic.
2) Any other consensus algo makes centralisation
Bitcoin is central already with 4 mining pools get all the blocks with mainly global players like Bitmain
To be fair, PoW is protected with game theory where miners would rather being honest and earn steady income rather than attempt double-spend/51% attack and risking Bitcoin price crashed.
I understand your argument and I would say its 50% right. Of course the ASIC energy consumption is less per TH.
But the HASH rate would never grown that much without ASIC the problems you say would people stop doing it this way.
So again if new Antminer come up or not for me there is no save of energy because simple the HASH rate will rise.
Completely wrong, even if there aren't any new ASIC hardware, total hashrate would increase if Bitcoin price increased or cheaper electricity price is found.