Actually your analogy is flawed. Because the way bitcoin works you have to pay some energy cost per block and you have a limited time to use that block because the next block will be coming in in 10 mins. It would be more like we had to make new coins every 10 mins.
Bitcoin probably is not fixable, but other designs are much better at supporting cheap transactions. There is nothing inherently expensive in maintaining the block chain.
this thread is about bitcoins. So I thought its implied we are talking about bitcoin. Maintaining a POW block chain is inherently wasteful, but yes POS blockchains can maybe save this.
Even with bitcoins just consider what happens once all bitcoins are mined. Does the whole thing collapse? Or do bitcoins continue to be used similar to POS?
The block mining algorithm doesn't change, right? So I don't see how it will move to POS. That will require some sort of buy in from the users. Every time something new is introduced in Bitcoin the legacy remains and the new ideas fork the chain into their own thing. Usually these alternatives either die or ignored.
Or am I missing something here?