I feel justified turning this around on you and asking what is good about it? It's disposable media. In and out of brain in seconds. There are any number of better ways to waste time let alone ones that don't show you ads.
If I'm on the toilet not having a fun time, pardon me for wanting to see some cat videos instead of solving a Rubik's Cube, I guess?
But also, of course people aren't just using these apps in the bathroom, they are using them everywhere. If they didn't exist, you wouldn't miss scrolling the bathroom.
But I do maintain that there is a place for mindless time killing. Life is stressful, I'm constantly switching between different projects and responsibilities, and a few minutes of mindless scrolling is nice.
But it is very addicting and can very easily vacuum up many hours of time I can't get back.
Anyway, I'm a bit crusty about the world right now so sorta going off. Don't mind me.