It makes sense if you consider the possibility that through the anonymity of analytics YT is optimizing it’s website to keep children glued to tablets/smartphones. When a user pauses, show them something else to watch, they might be bored and about to start playing roblox. Also, if they switch videos it gives you more views to give to your creators, and you can lead the next vid with an ad. Need to get more ads to those impressionable little eyes!