For me it was Safari 18 that for the first time in its history didn't have all the annoying rendering difference or lag. And specifically 18.4 which eliminate most of it.

And the Safari 26 seems to be a little faster overall. Both on M2 Mac and even x86. So far 26.4 seems to be even faster from start page rendering to bookmarks and tabs.

Both Performance and Web features are going in the right direction. I just wish they spend on more time actual browser features for power users.