I’ve managed to stay away from macOS 26 (Tahoe) and it looks like macOS 27 (Golden Gate) might be safe to upgrade to. Apple appears to have listened to the Liquid Glass horror stories and fixed many (most?) of them.

Liquid Glass remains, of course (Apple UIs tend to last several generations), but it seems far more refined and less transparent which is as close to an admission of failure you’ll get from Apple I think. Either way, it seems almost pleasant to my eyes now. 

There’s no chance of me installing a developer or public beta, but come 27.1 I’ll probably give it a go. Assuming it supports a five year old M1 MacBook Pro that is.