Most of this concern is around certain public key cryptography algorithms which depend on math problems being extremely hard to solve but could in theory be mathematically solved (decrypted without the key) with a good enough quantum computer.
Disk encryption (AES etc) is symmetric and still only brute-force would work which can be made infeasible with a long enough key.
Brute-forcing symmetric encryption is a somewhat silly concept anyways, because each decryption is equally valid.