I love the idea of asics. Wait here me out.
In theory, Asics are better than Gpu and maybe more decentralized. Asic= consistent hashrate and loyalty to the chain. Asic mean that you are not into only for the money but to help the chain since you can only use the asic for that. In gpu you can switch any time to other gpu coins. Many gpu miners are into only for the money by using nicehash and auto switch pools. Asic are supposed to decentralized by the the fact more than one company are making them.
Right now the problem with Asic is that one company makes them-Bitmain. If Halong mining is one of the few key reason why bitcoin was against changing the algorithm. It might be one of the last test to show if Asic can truly be decentralized in theory.
I kinda like POS(crying out load bitcoin is going to use POS in its sidechain tech . )
But current POS has a flaw who know it could be made better. People are researching them. DPOS does look like one of the best types of POS
Currently POW is better in my opinion.
While yes POW does seems like an energy waste it not. This work is necessary to make the chain secure. In POS, the stakers who owns 10% of the supply will mint 10% of the supply, and won't cost them anything much.
In, POW you have to battle against everything. You have to buy new miners to keep up, pay electricity, cool the machines, buy new ones.

Pos makes it so that 51 attacks are harder bc they are little their investments on the line. Pow is somewhat even harsher. Not only will their rewards lower if 51% attack done, the coin down=machines useless. This is amplified by asic machines which effectively locks the minier rig to mine only that coin.
Pow can be improved even more by making useful mining aka finding primenumbers.

But I am disappointed none of the major crypto use useful mining :(
I hope it will be used one day.
And yes I might of copied and pasted some of my posts to make this comment to lazy to type it out :)