Linux is clearly great and can even be used by non techie elder people, but only if you can stick around in case they encounter any difficulty. Why? Because they can ask anyone to get some help on windows, but most people would be scared to even approach something they don’t know, so they wouldn’t help these old people on Linux.
Is it a shame? Yes, but that’s the reality.
I guess that if you put an elder on a prepared Linux computer with nothing more to setup, the elder would be perfectly fine using it. But if they want to add a program or anything, that’s when they gonna need your help and presence.