That’s outdated experience, these days dnf is nearly as fast as apt. (Though not, in my experience, as fast.) dnf does have the advantage, though, that Fedora packaging errs towards inclusion, rather than exclusion, of related packages. By default when you install something, you will also get all of the optional dependencies it supports. (That can be changed, of course, but it’s the default for a reason:) I can’t count the number of times I’ve been supporting someone using a Debian distro, and the problem turned out to be that they didn’t have some component of what they were using installed (think like Qt, Python packages, etc.), simply because when they installed The Thing™, apt gave them no indication that it wouldn’t be fully functional unless they also installed this other thing with a terrifyingly obscure name. When those same things are packaged for Fedora, typically anything that can be used with a given package is made at least a weak dependency — assuming it’s even broken out at all, which if they’re very tightly coupled it may not be. Debian seems to package anything separately that can be separated, Fedora tends to be slightly less granular — for the better, IMHO.
…But coming back to the original point, dnf is plenty fast these days. Deltarpms, OTOH, have extremely questionable utility They’re fundamentally a tradeoff: meager bandwidth savings in exchange for significantly more CPU cycles consumed during the package transaction. These days that’s a really terrible trade. I’d love to see the back of them.
As a general statement about gaming: Ubuntu is generally considered the flagship distro for gaming on Linux, and not without reason. Fedora is a true libre distro, proprietary codecs and software are generally restricted from being packaged in the official distro packages. Yes, there’s rpmfusion for that stuff, but that’s a volunteer effort on top of this volunteer effort, and still does not cater to the crowd who prefer to view Linux as a Windows-alternative OS where proprietary and free packages are given equal footing, attention, and support. Ubuntu does cater to that crowd, and they’re welcome to it.
Not to say that you can’t game on Fedora. You can. But it’s not the distro of choice for either game developers or gamers, and that’s fine as it’s not trying to be.