Yes, the question of "least stressful" does not make too much sense without specifying "for whom".

The folks I supply with computers are complete computer novices across the board.
Every single one got GNU/Linux, but many don't even know this. They know they have to click on the left-hand "Globe" button to start "The Internet" and to click on the Envelope button to get their mails presented.

From time to time, the news anchorman on TV would warn "PC users" of a new dangerous virus wreaking havoc. Will all PC owners please upgrade their AV. Consequently I get anxious calls, how would they do this. My response is: "Please don't you worry about such things. Enjoy."

So this group, albeit small, should perceive GNU/Linux as pretty little stressful. In fact, they are mostly not even aware there is an operating system.