I'm considering on finally dual-booting Linux on my main system and slowly learning and developing it to match my work needs.
I was looking at Arch to be that distro, because it was the most malleable and easy to learn on Virtual box and on a spare laptop, but this long-term program stability issue worries me.
Can you not just tag programs (like Kdenlive) to not update with the rest of programs when doing a system update?
If so, is it viable to do so like on Windows?
Can you? Yes. Should you for long periods of time? No. Linux distributions, meaning how programs are compiled and distributed, are different from Windows. Static compilation, where the program is independent from system libraries, is not a thing outside of very niche and barebones distros. Your programs update together with your system, trying to skirt around this is inviting trouble.
When I was using Arch, I set my package cache to keep enough iterations that I might roll back whatever is breaking my system and wait for a fix. Other package managers, e.g. dnf on Fedora, have a transaction history you can use for this. Never updated before doing work, just like I wouldn't do on Windows. This is harder to do on Arch because it doesn't support partial updates - you either update all of your packages or none of them.
The learning experience, if you're not planning on becoming a sysadmin, comes from adjusting to how Linux does things, which is different from any other major OS. Any distro will do for this. Learning where the things on your system are located and how to use the terminal for fixing minor shit take priority over assembling your system from the ground up. Installing Arch when you're already familiar with Linux might give you a better appreciation for its design.
Flatpak solves this by having the application run in a container with all of its dependencies inside. This introduces some extra complexity, and apps that depend on tight integration with the host environment might have some broken functionality. Autists also hate it because it's not minimal.
Or you could use a distribution that has actual quality control, i.e. literally anything other than Arch.
This is the part of DT's video that prompted me to look into it. He says that he installed the Flatpak version of Kdenlive and pixelated rendering persisted despite 1080p settings. Next, he claims that it must've probably been "due to ffmpeg on the system". Fishman, do you even know how flatpak works? This should've been the biggest red flag. 5 minutes of searching gets you a possible culprit in
this thread on the KDE forums. A bug in the GUI when setting custom quality, no distro is doing QA on graphical shit. He's also using some weird offshoot of Arch called Arco Linux on his work machine, which means less testing performed by distro maintainers. The absolute fucking state.