Emphatically no. The absolute vast majority of those "polished dropdowns" are horrible to use, and break all possible platform conventions (for example, not accessible or usable with a keyboard)
> countless other controls you interact with every day require javascript.
Very few, if any, "polished controls" used on the absolute vast majority of web sites require javascript.
"Dropdowns are toggleable, contextual overlays for displaying lists of links and more. They’re made interactive with the included Bootstrap dropdown JavaScript plugin"
- don't follow platform conventions (don't trigger the actual system dropdowns with actual expected behavior)
- get cutoff by browser chrome when page is zoomed in (because you can't control that behavior from JS)
- default implementation's touch targets are too small
And that's for a framework which has had over a decade to make this work.
This is not to throw undue shade: they've done a very good job. But that's about as far as you can get.