Factoring big numbers can be highly accelerated with quantum computers and Shor's algorithm.
https://en.wikipedia.org/wiki/Shor%27s_algorithmIn my opinion new POW algorithms should not only be ASIC resistant, they should also be quantum computing resistant.
Bitcoin would already suffer if some day quantum computers with enough qubits become reality as the private/public keys could be cracked with Shor's algorithm.
The SHA-256 hashing of the public key would prevent this attack, but there are already lot of public keys revealed which still contain balances (very old transactions, reused bitcoin addresses). And with those known public keys the private keys could be calculated.
Also RSA encryption (used for example in HTTPS connections) could be cracked quite easly with Shor's algorithm which might be the best what could happen to our nice three letter agencies to globally spy on every online connection.
It might still take long time until quantum computers with enough qubits are available, but we should try to avoid not quantum computing proof algorithms when creating new stuff.