While generally I'd agree with you, these apps are engineered to exploit human weaknesses to make a few people money and have real and measurable effects on the human psyche. From reduced attention spans due to short form or dense content, to problems with self-worth, these apps are literally bad for you if you engage with them a lot - which, again, they are engineered to get you to do. They are completely manipulative and not "just another fun thing".

You can also have fun by reading a book. Or making something. Or going out.