I guess Desktop Linux's biggest hurdle is that most people have no idea it even exists, and there's zero advertising.
Because of time and inevitable changes happening to everything over time.
Remember when Windows was nothing and everyone was using something else? Remember when macOS was nothing and everyone was using something else? Same thing can happen with Linux, or some other operating system. Sure, might take 10, 50, 100 years, but eventually, Windows and macOS (and probably Linux) will be relics of the past.
Things get A LOT more complicated when you add localisation, accessibility, UI and all the other things we take for granted.
They're technical people, and yes, LTT is hammed up a bit (I call it the Top Gear of Tech), but the number of issues they ran into that you just don't on Windows (in most cases) was illuminating.
I have no troubles running a Linux home server, but I don't have time to fiddle around so my gaming desktop is Windows, and for work it's MacOS.
This thinking is really obsolete and couching everything as grandma or graybeards is really ageist, anyway. Last I looked, you have to do this on Mac more often than I'd like. On Windows, it's open up CMD as administrator and paste this command or download and install this little app and run it (that does God knows what as administrator).
Maybe I've become numb to them, but I just don't see these painful interactions that get referenced, and don't see why their bogeyman would be worth giving up your freedom to use your machine.
Systemd, netplan, and many other things.
I am not sure what UNIX clones have to do with this
The latest version of Ubuntu you can not even set the IP with standard etc config, you have to use netplan YAML configuration
systemd has replaced all kinds of things with non "grey beard" configurations,
the list is pretty extensive
It's roughly a 50/50 split for the rest between Windows and macOS.
So how can it be remotely plausible that Linux will become a mainstream desktop/laptop OS?
Non IT workers also seem to favour a combo of phones and tablets too only using laptops for work not caring what it runs.