Some distros manage to get it right. I haven't had any trouble using OpenSUSE Tumbleweed's packaged Firefox.
All this talk of snaps and using PPAs sounds like a an unnecessary headache. What’s the point of a package manager if it doesn’t keep your packages up to date?
I run Debian stable on my workstation, and manage most of my packages with `apt`. As such, everything "just works," and flawlessly.
For the handful of packages that I want to upgrade aggressively, I manage them with Nix[1].
I've been doing this for maybe two or three years, and despite a little extra complexity, it feels like a best-of-both worlds scenario. I get the rock-solid stability of Debian stable, but the one or two packages that need to stay cutting-edge are able to do so.
I also don't have trouble with package conflicts, because the entire point of Nix is to prevent those kinds of problems.
This has been great for me. Do recommend.