Personally I've always been kind of confused by the common best practice of separating everything. React and Vue single file components made so much sense to me.
I guess if I were to rationalize my position, I'd say it's because I have a hard time finding related things when they're separate. If a button or "a" tag have a special click handler, I want to know when looking at it. If it just has classes, then I don't know if that are for style or if they're for behavior. I know there are some conventions out there where you prefix classes with "js-" etc, but if you just use "onclick" then it's obvious and you don't need a convention.
I guess if I were to rationalize my position, I'd say it's because I have a hard time finding related things when they're separate. If a button or "a" tag have a special click handler, I want to know when looking at it. If it just has classes, then I don't know if that are for style or if they're for behavior. I know there are some conventions out there where you prefix classes with "js-" etc, but if you just use "onclick" then it's obvious and you don't need a convention.