Saying sha256 isn't doesn't make sense.

Once quantum computers are a real thing, #Bitcoin and every shirtcoin out there will switch to a quantum resistant algo.

The issue is, monero old blockchain will become readable. ALL your transactions are nicely stored and are waiting for this disaster to happen. And what the monero node runners do? They're nicely storing all your transactions for everyone to read in the future.

Do you want to break the link? Use #Bitcoin LN in the middle. The records are not stored there forever, there's no blockchain on lightning.