Google "don't be evil". Yeah right. Youtube has added 5 second delay if you use Firefox as a browser (instead of Chrome).

https://old.reddit.com/r/youtube/comments/17z8hsz/youtube_has_started_to_artificially_slow_down/ - technical finding in https://old.reddit.com/r/firefox/comments/17ywbjj/comment/k9w3ei4/?utm_source=share&utm_medium=web2x&context=3