I have read Which reasons were discussed for potentially changing the proof-of-work algorithm? but aside from being more asic 'resistant' and faster to verify what other reason should monero change pow? With quantum computers a pow hardfork will need to happen, is cuckoo cycle resistant to quantum computers? Is there any pow that is quantum computer 'safe' and also have qualities that monero needs? fast verify, asic 'resistant' etc etc etc thankss
The arrival of quantum computers (QC) isn't necessarily a reason to change the PoW. It would only be necessary if the first generation of quantum computers are so fast that only a small investment is required to attack the network.
That scenario would allow the first person to build / buy a QC to attack the network.
If on the other hand--and I think this is the more likely scenario--the first generation of QC are better, but only by say an order of magnitude, then we'll see a gradual upgrade of mining nodes on the network, where nobody is ever in a position to attack the network.
So if QC becomes commodity hardware (e.g. most systems now have a CPU, GPU and QC, specialized for different tasks) do we really need to change the PoW just to make it viable to mine using only a CPU or a GPU?
The answer, I think, is no. If we change the POW so they're all equivalent in performance, it would increase the security added by each compute node by a factor of 3 (CPU, GPU and QC utilized instead of just QC), but it would do nothing for decentralization.