It's helping teach my five year old patience and not to flail around hitting the keyboard when something doesn't happen immediately. He only gets to watch videos and playlists I search out for him, and only when I'm in the room... no YouTube Kids here. Once he's able to spell well enough to search, I'll have to re-adjust.

I have found, and this might just be psychological, that if I hit pause, wait a second, then play, the video starts playing within a few seconds.