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.

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.

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.