Steam

What is it about reddit-style social media that brings out the obnoxious le redditeur archetypes? You're just talking out of your ass and being snarky about it. Peak redditing.

Let’s start with a baseline: monopolies are not illegal. Let’s say that again: monopolies are not illegal. If that is your point, “you’re wrong”.

Putting words in my mouth. I didn't say monopolies are illegal, you just made that up to be snarky. The rest of your comment is just you pulling stuff out of your ass with no kind of citation whatsoever.

When the government tries to pursue a case to try and break up a monopoly, they're not trying to prove that the company fits some textbook definition of the word "monopoly". That'd be stupid, and lawyers may be a lot of things, but "stupid" generally isn't one of them.

They start by defining a specific market or markets that the company participates in, showing consumer harms (aka the consumer welfare standard, which actually sucks and the Biden admin was trying to correct, but whatever) by the company's business practices/structure, and recommending remedies, like a break up. So it technically doesn't even have to do with the size of a company or their market share (although that's usually a major component).

So, before we even begin, we can see that this does not really apply to Valve. Valve has competition

Again, this conclusion is based on your incorrect understanding of how antitrust regulation works. So there's no point in me correcting the rest of your post. Instead, I'll summarize and translate it into what I think you actually wanted to say:

"I like Valve and you're a meanie for implying they're doing something bad"