The point is that Epic complaining about being unable to compete with Steam, and therefore needing to employee anti-competitive, anti-consumer practices rings a little hollow given that they have significantly more resources available.
I'm not here to stan for either company, I think if Epic wants to compete they need to create a better product, not fling monopoly accusation while actively pursuing monopolistic strategies.
Making a platform that was simply a copy of all of Steam's features would certainly take a lot of time. That's why to break into the space a new platform would need to actually innovate a killer feature that brings early adopters to it even without having all the bells and whistles Steam has. Then the user base can and will grow as you fill in the gaps so the 'sacrifice' of using your platform is lessened.
All exclusive games do is build resentment in your customers at being forced to use an inferior product.