When I first started using Linux 15 years ago (Ubuntu) , if there was some software you wanted that wasn’t in the distro’s repos you can probably bet that there was a PPA you could add to your system in order to get it.
Seems that nowadays this is basically dead. Some people provide appimage, snap or flatpak but these don’t integrate well into the system at all and don’t integrate with the system updater.
I use Spek for audio analysis and yesterday it told me I didn’t have permission to read a file, I a directory that I owned, that I definitely have permission to read. Took me ages to realise it was because Spek was a snap.
I get that these new package formats provide all the dependencies an app needs, but PPAs felt more centralised and integrated in terms of system updates and the system itself. Have they just fallen out of favour?
Another issue I’ve had with Snaps is just increased boot times. Something to do with mounting all the virtual images involved or something, makes boot take noticeably longer. I’ve tested having an Ubuntu install with Snaps, and then removed the snaps and snapd while installing the same software via Flatpak, and had a noticeable boot time improvement. Hopefully they’ve been working to improve this, but it just soured me on them even more.
As for another install method, mostly for CLI tools, but working with a lot of GUI apps too now, there’s Distrobox. It has a bit of a bloat issue, because you’re basically installing an entire extra headless Linux Distro with it, but it for example allows you to run AUR inside an Arch based Box, and then you can integrate the app you installed with AUR into the host OS, running it near seamlessly, while keeping its dependencies contained in the Box which you can easily remove. By default apps in the Box will have access to the host’s filesystem but you can mitigate this if you want. Distrobox is especially great on atomic read-only Distros, where you can’t directly touch system directories, by allowing you to install apps that expect such access from things like AUR.