> Linux is a great "fire-and-forget" OS for situations tech-illiterate loved ones.

Only if the device is truly 'forgotten'. As in, it is an appliance that's going to do that task forever and ever. Be it web browsing or what have you.

If requirements change, it becomes a problem. If they have to do work on them and interact with companies, you may need either Windows or Linux. Thankfully online Office365 removed a big use-case. But there are others. It is very likely that whatever package you need will be available on Windows or OSX.