Yes, it's unhealthy for the undustry even if you enjoy it today. Gabe newel is old. He's going to retire soon and likely sell the company. You won't like what happens after that, and the fact that so much of the industry is provided via their product means they have a lot of agency to tighten the screws.

"OH but then we'll just use something else". That's not how the monopoly works, you might, most won't. Most of what you want won't be on the something else.