Mpv – A free, open-source, and cross-platform media player

Can it do smooth scrubbing (i.e. scrolling the progress bar)?

So many media players only show the key frames when scrubbing, making it a much less pleasant experience. Some mobile phones (Apple, Samsung) built-in media players seem to do it nicely, but I've never found a desktop media player that does it (VLC can't).

Probably would require a lot of extra decoding behind the scenes to extract all the frames, but worth it on a modern machine.

I don't believe the scrollwheel works to seek video, not sure, but MPV can go frame by frame. It's bound to the keyboard by default, but you can tweak your config and bind it to the scrollwheel.