That's where I disagree.
First of all, Humble is a storefront, not really a platform.
GoG and Itch.io are but they never tried to compete with Steam, rather than being their own thing, offering a different service.
And on top of that, Humble and Itch.io never try to disrupt the market by fragmenting it. Buying on Humble (which I do far more than buying on Steam) or Itch.io provides me Steam keys to redeem on Steam and still have access to my amazing services.
As for the rest, you're right. If Epic bought everything, they could force people to come to their client. But that's not competition anymore. With such a move, how do you make Valve to improve Steam (because after all, that's what some people seems to ask for ?). You compete on the same turf, and if Epic's way of competing is buying exclusives, then it means if Valve wants to compete it'll be on the same turf. And instead of competition, we'll have another case of small monopolies.
As for it being the way to do thing, I disagree highly that services aren't that important.
People need to remember how PC gaming was in 2008-2011. High piracy rates, Western publishers leaving the platform.
Heck, just some quotes:
https://www.pcgamer.com/pc-gaming-has-around-a-93-95-per-cent-piracy-rate-claims-ubisoft-ceo/
And one from our dear saviors competition:
https://bit-tech.net/news/gaming/pc/epic-pc-piracy-drove-us-to-consoles/1/
What did make people come back to buying games ?
Sure, sales helped but not as much as people might think.
After all, free is cheaper than 5 dollars.
The answer is the service. The service makes the game have MORE values. It becomes a legit product compared to the counterfeit pirate version. And the legit product is easier to get than the counterfeit one.
Now if you rely only on a launcher and a buying spree, here's what happens: You raise piracy again. Because what's the difference between the game bought on Epic Store and on illegal download sites ? The price only.
Heck, in the case of Bethesda, since you dont have to rely on their broken launcher, the illegal version is even a better product.
A fragmented PC market by artificial constraints such as buying out exclusivity, without any convenience and good services leads to only one thing: Piracy.
That's something I hear (dont quote me on that) that is happening with streaming platforms since they keep spawning everywhere and making it a hassle for people.
Ideally, if a storefront dont want to compete on the service side, then they better just rely on Steam keys and not fuckin up the market. Heck, Epic Game Store would be a more appealing offer if, despite the horrible moneyhating, they were using Steam keys.
Instead Epic seems to think the good thing is no service and bringing devs in the hope it brings customers. The only thing that kind of strategy brings is more piracy.