How is that in any way fun?
They are basically weaponized progression systems in games. its like the "ding" in EQ. as well as the discussion of how rewards in games should be timed out. like, typical mmo of 1-5 levels gained in 10 minutes, then leveling up is slowed as more effort is put into the game. And, similar with item rewards systems.
They eliminate all the extras. Click mouse. Level up.
Shit goes right to the autism center of peoples brains, and makes them, "one more", "must hit max level"
generally they expand to be efficiency managers. as you try to maximize clicks.
Also, most often expand in ludicrous ways. Paperclip one, opens into several minigames. goes total grey goo scenario, as you destroy earth, the universe and create sentient AI, and then destroy it..(spoiler) Cookie clicker, you also destroy the universe as you turn the universe into demonic cookies.
Loolipop one has a hidden RPG in it.