It's one of those changes that will happen sooner or later, bazzite and steam need to figure out a solution because fedora, and other modern distros can't and won't keep dragging around 32 bit libraries forever.
imecth
Fedora doesn't enable non free repositories by default, and that's a big deal for new users. Telling someone they need to run commands in the terminal to get their nvidia drivers, or even get youtube working is a problem.
Even if it's out of beta for 26.04, you'll probably want to wait a few releases before giving it a go. It's bound to be quite unstable for a few years.
low-effort
People always underestimate the work that goes into making sure stuff works. These packages need to be built so they add a lot of compile time to the pipeline, these packages have limitations inherent to 32 bits so they also add troubleshooting and bugs. This is time and resources that could be spent elsewhere.
Apparently there's a few problems with the flatpak version, like you can't ~~run gamescope or~~ start a steam big picture session.
That's not the point, dxvk isn't gonna get used at all if the game is running dx12 or native vulkan.
I think the real problem here, for devs anyways, is that you have people that have 8gb and people that have 16gb, and everything in between, which makes optimizing much harder than they'd want unlike a stable target like a console.
People making an informed choice about linux vs windows are a minority, the majority just don't realize switching is even an option let alone have the technical know-how to go through with it. As long as windows comes pre installed, nothing will touch its hegemony.
Hey, you brought it up.
So, why are you friendly to Epic?
There's plenty of different solutions, but anything that isn't what people already have is gonna upset.