If they had even half of Steam’s user base they would be profitable. Their problem is that gamers insist on backing Valve’s monopoly because it’s what other gamers tell them to do online.

Well, see, here’s your first mistake; you think Valve has a monopoly. But they’re just one store out of many, including game console stores. The difference is they’re actually providing a good service.

Yes, it’s shocking; people tend to gravitate towards the service that’s actually good!

And Epic provides Unreal Engine, the gaming engine that powers the majority of modern games…

And what a total shite of an engine that is. It’s actively destroying the gaming industry by emphasising all the worst development practices gamers have complained about for the past 8 years.

… with free and extremely cheap tiers for indie devs…

Just like with their service fee, they’re doing this to completely undercut competitors, to ensure the Game engine everyone used is Unreal.

This isn’t a good thing.

… they provide explicit Linux support…

No they don’t. They barely support Linux with some elements. But Unreal Engine runs like absolute shit on Linux, if at all, and Tim Sweeny infamously hates Linux with a passion. He has some personal grudge against it.

They’ve also used a substantial amount of their Fortnite money to break up app store monopolies…

Because they want Fortnite to be the one game young people play. The One Live Service To Rule Them All. The only way they can do that, to reach the maximum amount of the youngest generations to squeeze them and their parents for all their money, is to be as widely available as possible.

Valve got skin gambling. Epic got Fortnite. The latter involves children and is massively more profitable.