While I can’t provide you with a proper scientific answer I can offer a basic explanation - it’s effort.

Browsing through the never ending amount of content online requires no effort but provides you with a dopamine rush as if you actually managed to accomplish or do something with your time. Other stuff, like watching movies, playing games, reading books, etc. requires attention and active participation, the payoff on the other hand is largely delayed (especially compared to the lazy option).

As for hacks… I don’t know any. The only ways I know how to deal with it is limiting your time scrolling through this stuff and forcing yourself to do other things - it can be rough early on but you’ll eventually get used to the “normal” way of functioning.