[smileypete]

Seems Youtube has gotten slower for me over the years... Playing an HD video Firefox 55 (w/classic, MP4) uses 30%, Chrome 70 uses 20%, but Videolan uses a mere 4%!

It's puzzling why a modern browser uses far more CPU than a standalone app these days.

[dhnsmakala]

Did you compare the baseline browser usage to browser + video?

[smileypete]

Just a clean restart then a single tab for youtube, and looking at the total CPU in Process Hacker.