not that big of a deal if you choose a distro with good defaults ootb. choosing the right distro is the biggest step imo if you don't want to debug your computer.

The thing is it's the same base linux as decade(s?) ago, windows is changing how stuff is done all the time.

So a one time effort or a marathon IMO.

I don't think my grandma was a sysadmin.

Really depends on your use case. Like @trougnouf@lemmy.world said, casual users that use the OS as a browser and email client can use practically any distro. Users that do a bit more, like casual gaming on gold-rated Steam games, generally do fine with something like Pop!_OS or Linux Mint.

It's when you start going towards the more hardcore users, like really hardcore gamers that play obscure titles or have unsupported Windows-specific hardware, artists that need very specific unsupported programs for editing or recording, engineers who need to do CAD specifically in a Windows-specific proprietary software, or a tinkerer that's used to the Windows environment, that "become a sysadmin" starts being a reasonable complaint.