You can choose not to use bookmarks, remove the bar reserved for it, and it’s taking up kilobytes in the background. Can’t say the same about shoving an LLM in a browser.
But sure, I’m much closer to the extreme of “make bookmarks a plug-in” than “make everything a default”.
I don't use bookmarks. Should those be opt-in? What about the other 85% of the browser's features I don't use?