"MacOS 26 being super sluggish" is the kind of thing I only read here on this website. For me and everybody I know who upgraded to it it's running fine.
The only device I’ve found more sluggish after this recent OS upgrade is my Apple Watch Ultra (gen 1).
Animations when navigating the OS are noticeably sluggish where the previous version was smooth as butter. This degradation has persisted through multiple minor version updates since, so it seems to be permanent.
Disappointing for what is marketed as the most powerful watch in their lineup.