Also… the actual good stuff has a good chance of not being free, or not being on YouTube—it’s just the reality of our world.
When you look for YouTube videos of random people, you can get anything, from good programmers to horrible ones. You can’t really require quality from strangers posting stuff for fun.
But for apps distributed in your system’s package manager, it’s not the devs that are distributing them in every package manager. It’s the distribution itself that goes to each repository, checks and tests the dependencies they need and creates the package for the distribution, along with a compiled binary.
When they aren’t offered in the distro’s package manager (or the version is outdated because the distro isn’t rolling release) things become more complicated indeed, and sometimes you can’t even do it because the dependencies are older than the ones you require.