Both Flatpak and Snap are preinstalled but it defaults to debs/apt. Though through the command line they strongly recommend the pkcon command over apt itself.

So… it sounds like you’re struggling with Snap. In addition to others’ suggestion (try a different distro without Snap, perhaps one of those distros made by a different company such as Fedora (Red Hat), an OpenSUSE variety (SUSE), or even a corporate, less Snap-reliant Ubuntu-based distro like Pop_OS (System 76)), you could also try uninstalling Snap from Ubuntu or installing another binary option like Flatpak/Flathub and installing your software that way. Frankly, the amount of money these companies make working on Linux or Linux-based products has nothing to do with your struggles. Plus, the companies you mention do, in fact, make money working on the kernel itself because they contribute to the kernel as a project. Even Microsoft and Google do the same, though Microsoft does so for the sake of WSL and Google does for Chrome OS and Android. So plenty of people make money if the Linux kernel keeps having work done on it and keeps improving. I don’t see what the problem is with the kernel itself. The lack of polish, as you call it, in Linux-based OSes is not a fault at all of the kernel but in all the various other parts that go into the OS. And that level of polish can vary quite widely. As you note, Snap has been holding Ubuntu back quite a bit due to lack and reluctance of community adoption. Even just trying a different Ubuntu-based OS such as Pop_OS, Linux Mint or Neon may change your view.

Flathub is likely safer than most other places to get flatpaks from, certainly safer than just some random repo you find on some guy’s website somewhere, but no software source is guaranteed to be 100% safe.

OSMAnd is how I use OpenStreetMap too. It’s quite good for road routes even in rural areas, but especially in those rural areas finding specific locations can be spotty or outdated. Even in my town of over 100,000, I still have trouble finding some local places like restaurants and businesses. I always try searching for what I’m looking for before I leave home, so I have access to my computer to pull up a map and address to pin onto OSMAnd if I need to. (I’m someone who de-Googles as much as humanly possible so I don’t use Google Maps.) With more up-to-date data it can be a great alternative to Google or Apple Maps, but that’s the nature of crowd built data: it’s only as up-to-date as the data contributors provide, and that’s both a strength and a weakness of OSM.

Windows Vista completely died on my laptop back in 2009. I’d vaguely heard about this other OS called “Ubuntu” shortly before that seemed neat and was especially cool because it was free, but was too nervous about breaking my machine to try it before, but because it was already broken at that point, I had a friend burn me an ISO and installed it. I learned Ubuntu was actually Linux when I was configuring and learning how to use it, and that’s when I learned about concepts like FOSS, Linux just being a kernel and not the whole OS, and the idea of Linux distros. The only time I looked back was dual booting a gaming PC with Windows 10 for a while just before Proton came on the scene. Even then, booting into Windows was rare, only for games that did not work on Linux at the time, which with Proton releasing and constantly improving, became even rarer as time went on. A failed distro upgrade last year (likely due to me messing around with Mesa driver versions) finally had me wipe the Windows side from that PC altogether and go back to only running Linux when I clean installed over both Windows and the other broken Linux install. Truly haven’t looked back since.