They at least reveal it when publishing a spending transaction, opening a roughly 10 minute window for finding the private key and publishing a double spend with a much higher fee to steal the funds.
What "other methods"?
P2PKH,P2SH,P2WPKH,P2WSH,P2TR
> Spelunking for Bitcoin by generating all possible keys and checking their account balances is not prevented by PQ algorithms.
And how will you solve this?
Quantum computers are not magic.
Only quadratic speedup for most problems, like search. That's why hash functions with key size 256 or higher are safe, for example.