Most Ubuntu based distros let you just double click on the deb and just install the deb file. I don’t see how that’s appreciably different than Windows.
This page presupposes that the graphics tool to install .deb packages is not preinstalled, which isn't true for either Ubuntu nor Mint. If it is preinstalled the steps are really just "double click on it and then click install".
Same thing for RPM distros. So the only real catch is knowing which package to download.
It's possible the image could autodetect the OS (or even autodetect the presence of a package manager) and present a single option to download or launch the package manager into the right screen, which would then put Linux at parity with MacOS or Windows, but currently it can't.
It's definitely harder than those things, and lots of regular people struggle even with them.
