First of all. I don't agree with MarsMan and I think what he is doing is straightforward market manipulation.
But one thing is o/c right in this whole mess. Proof of Work can't be Bitcoins destination. First of all one question is if it really still fulfills its function for decentralization. Is a system truly decentralized or distributed when there is already just a handful of groups that would just need to agree on common terms?
Energy might be another factor and important as well, so a less power hungry solution might be great, on the other side it could be very healthy to the renewables industry if all miners would be forced to use only green energy, since this would generate a significant amount of money flowing into those industries. But I don't see any technical way to really enforce that.
I am a long term user since Bitcoins inception, but I stopped following the development for some years now and hold most of my assets I bought for a few cents years ago and just do some trading from time to time. So I might be not up to date if there are efforts to move away from PoW. Can someone give me an update on this? If Bitcoin is not considering to move and evolve, what are your takes on this and why would one cling to much to PoW, just b/c of the hard fork it requires? Or are the alternatives still not mature enough?
Not sure why you think Bitcoin is "clinging" to PoW. PoW is not a bad thing. It is a rather uninformed take to think PoW is bad and something that must be moved away from. There only needs to be one proof of work chain, and Bitcoin is it.
PoW provides global-level security.
It allows Bitcoin to be highly decentralized and have its security rooted in physical reality.
It separates the minters of coins from the owners of coins (for example, PoS is a "the rich get richer" system by making the holders be the minters of new coins, not saying that is bad or good, but Bitcoin separates the two which is a nice difference).
PoW also makes Bitcoin a literal energy-to-money conversion machine, and having a system that can directly convert energy into money is a very powerful economic tool, especially over the coming decades as the world works on moving to renewables. You don't enforce renewable usage, Bitcoin naturally encourages renewable energy production because it makes the spread of renewable energy more economically viable - I should say it makes energy production in general more viable, but as the world is trying to switch to renewables this naturally favors the spread of renewables.
So, no, there are no efforts to move Bitcoin away from PoW, because there is no desire to move Bitcoin away from PoW, because there is no need to move Bitcoin away from PoW. The only people who want to move Bitcoin away from PoW are the people who don't participate in the Bitcoin network in any way - which is to say nocoiners, because they don't get what Bitcoin is all about, so they don't understand PoW.
As you can see from the Ethereum upgrade, changing consensus mechanisms is a huge complicated undertaking, and Bitcoin is much more stable and moves much more slowly that any other blockchain because it is so important, so valuable, and it's value is partially reliant on it being so stable. So there is no need to put the Bitcoin network in potential harms way in order to do a very complicated and entirely unnecessary consensus change.
PoW is not a bad things that Bitcoin clings to against rationality. PoW is a fundamental part of Bitcoin's power, security, value, and importance to society.