I taught my mother to use CP/M, MS-Dos and Windows. I don't know Apple products, because I was never interested and never learned. Starting out one needs to learn Windows (and the changes with each version change), Linux, Mac, or Chrome, or whatever. The learning curve is there whatever the OS.
If you start with Gentoo or various other distros the learning curve is going to be a lot harder - that is the new user's choice. I can and do use Libreoffice, Gimp, Freeplane, Thunderbird, and dozens of other programs on both Linux and Windows. And I don't even mess with the various tricks for
getting Windows programs to run on Linux. If you can't live without MS Office, Microsoft 365 works with Linux, or at least it did the last time I tested it. Of course MS could 'fix' that. Lots of programs however are available across the three main OSes.