nix doesnt have any of these, but sandboxing is hard, there is either stable or unstable, changing and configuring things is very complex. Likely no official packages. Still the method I prefer.
Nix is what I use, and it was frustrating to have to hack a lot of it into place, but I feel like it has the most potential. Unfortunately the flakes nonflakes split, in combination with the split of "distros" like determinate nix, flox, and so on, and the governance concerns really hold it back. It has horrific documentation, for the most part caused by the above (flakes are "experimental" and so can't be included in official docs), and it is frustrating the lengths I have to go to to make stuff work that should be easy.
For example, GPU acceleration of Nix packaged apps on non Nixos systems. I figured out how to do it:
(config.lib.nixGL.wrappers.mesa pkgs.gzdoom)
source
But I think it's just straight up impossible to do this via imperative package installs, outside of home manager. And it's kind off important if you want any GUI app whatsoever to work.
But now that I have it working, I use Nixpkgs exclusively and am able to avoid the AUR entirely. To me, the AUR is a last resort, only for something like say, system level printer drivers (thankfully I've never needed to install anything to get printers to work). By ensuring that I only use the AUR once in a blue moon, I can make sure that I actually review the PKGBUILD when using it.