I know this is a game forum, so I guess some people won't like my answer.
If we set the definition of "waste of time" as something that does not create value, sure, almost anything is considered "waste of time", like hanging out with friends.
But if we consider "waste of time" as poor/low quality of entertainment, I agree that gaming is "waste of time", sure, this is 100% personal, but let me explain my point of view: besides the practical use, it's all about the memories you retain after you do the activity, gaming in this case.
In my case, I could play a game with low/high graphics, or good/bad mechanics, but what stays with me after time passes is the plot/story and world builing of that universe created, and I think that the time used to build those memories are less effective as reading directly those stories. In other words, I think reading values more of my time than gaming, but it's a double edge sword, reading creates less dopamine than gaming, which means that is easier to play for 5 hours comparing to read for 5 hours.
At least for now, I'm trying to decrease my level of dopamine to make real life things (not digital ones) more appealing, which means books, hobbies, and so on.
Besides of what I wrote before, I still play games, why? because is something that I grow up doing and it is my last resort, the solid "fundation" I was built uppon.