That's the problem. The Linux way of distributing apps is wrong for trying to compete with the other consumer platforms. The ChromeOS or electron style of doing things is another story though.
If you have a stable widely used application suitable for being installed by unsophisticated consumers, have the distributions put it in their package managers. This is hardly any different than consumer mobile platforms that require you to use an app store, except that it isn't actually required, just the thing you ought to do absent a good reason to do otherwise.
If you're distributing something sufficiently esoteric or experimental that the package managers won't touch it, your correspondingly sophisticated or adventurous users can compile it from source.
We don't need some malware-facilitating norm that encourages users to install opaque binaries from random websites.
Each distribution is a different operating system. You cannot package the "same" app for Windows and mac, so why should you be able to package the same application for Debian and Arch, which, even though they run a lot of the same code, have different underlying layers and assumptions?