I'm a rabid anti-gamer and I will tell you they are a gateway drug to antiproductivity.
I have spent many hours playing games and I used to regret that, but looking back I had fun with friends and was still able to get good grades and stay active.
I would take games over TV any day!
The only scenarios where I think they're beneficial is when they're enjoyed with friends (preferably in-person), or for the elderly to help with hand-eye coordination and keeping their minds active and busy.
I think this focus on hyper-productivity as some form of ideal is a sad way of approaching life and self-worth.
You can always pursue less productive outlets when you have a job.
The digital resources that don't cost you money also allow you to build things and think through things you otherwise couldn't. This is Minecraft's big appeal. You can't necessarily cut down the trees in your real yard, build structures without permits, and so on.
Games with online social elements also present similar benefits to hanging out with people. If you're fighting monsters with a group, you may talk about all sorts of things in your downtime.
Not strictly true. Games are fun because they are a learning experience. Boredom is the result of having learned all that is learnable from a thing, and frustration is the result of continually failing to learn from a thing. In this sense, all games are teaching or honing skills, just ask anyone who's finished Getting Over it With Bennett Foddy.
You may argue that games teach "worthless" skills, but I would say the same is true of many hobbies and, moreover, not everything valuable is valuable because it can be put on a resume.
This is also true of: (recreational) sports, reading, social interaction, and probably the majority of recreational activities. The entire point is to have fun, because having fun is important.