To a certain extent this is correct, especially if this person works or used to work an office job in the last let's say 15 years. But even then what are the use cases of office suites at home, mainly writing letters and maybe for the slightly more tech literate something like logging personal finances in a spreadsheet. In case of writing a letter those files are usually printed and the spreadsheet are usually considered confidential data. These people rarely, if ever, share those files with anyone, so interoperability is likely not an issue.

I'm therefore convinced if you just guide those persons to e.g. libre office writer and just say that's "The word" on this machine, they're going to be fine with it. Also almost all of these people use webmail instead of mail clients so the absence of Outlook is usually also not a problem.

Imho this includes 90% of the 50+ years computer user that can be migrated to Linux this way. The "problematic" ones are the ones who know some stuff, like how to click by click import my mail account into Outlook 2016 and want their new computer to behave exactly the same way and will go bananas otherwise. If I encounter one of those in my circle of relatives who need help with their computer I usually just leave them with their windows 7 machines or whatever they're using cause it's not a battle worth fighting.