Sure, for things that are packaged in your distro’s repositories the best option is to use your package manager. As it is, that requires a ton of effort on their part and will never include every piece of software available for Linux. Cross-distribution solutions are necessary so an application developer can simply release a version for Linux and leave it at that, rather than releasing a .deb and maybe a .rpm and leaving everyone else to either build it themselves or hope someone decides to package and maintain it for their distro.

I don’t mean this as an insult, but I think you missed what they’re talking about entirely. This isn’t saying apt or whatever is too hard for the user to use. It’s comparing the different solutions that are out there to make up for the gaps in that model.