I have this feeling that Linux only plays a role for programmers and sys admins. There also is the administration of Munich, which uses its own Linux distribution, but in my personal circle all Linux users are either dev and admin.
I've made a version of their Raspbian OS just for my older, not very techie, friends to replace their old Mac/Windows PCs when they die.
There isn't an affordable new Mac now and I've spent less than 10 hours on a Windows box in the past 20 years so I can't help them when they die, but I can set them up with a brand new Pi for around $100 (+ or - a few bucks) and they all love them. All they want to do is surf the web, FB, email, and YouTube.
The latest versions of Raspbian have incorporated so many of the mods I worked on over the years that now I really don't have to do anything much more than hide what they'll never use.
Aside from those, I don't know anyone off hand I can think of.
My first reaction to Windows 3.0 and 3.1 was horror. It was so primitive and so far behind the X11 Windowing System that I was never able to accept Windows as a personal system, but only used it when forced to at various work-places.
I used UNIX with X11 (AT&T, USL, then Solaris) solely as my personal system until 2001 when I changed to using Linux.
I could be considered as a techy, but was never a true computing/programming professional.
When their laptops were getting too old for the latest Windows, I switched them to lightweight Ubuntu releases - Lubuntu and ChaletOS - after a trial period and feedback. I configured both to be as close as possible to their old Windows workflows. I gave them the choice to stay with Windows if they wished, but both said they prefer the faster Ubuntu experience. Thanks to Dosbox and Wine, my father can even run his 1980s BASICA math programs on it. They don't have any problem whatsoever.
I think one of their biggest issues is that they had made their own Linux distribution. That is really surprising, and is not the sort of forward-thinking and trendy project that a government organisation anywhere in the world would normally undertake.
If they used something like Ubuntu with paid support from Canonical, many of the issues they were facing might have been more easily solvable.
In regards to your question, a few years ago I set up Ubuntu Linux for a young family friend (still a child), and they have been fine.
They had never really gotten used to Windows and picked up the bad habits, so the transition was pretty easy. They don't do anything 'advanced' though, they just use the software that I pre-installed for them (Chrome, Steam, etc) and install updates when they are prompted. They never touch the terminal or anything.
But whether scientists are "in tech" seems to depend on who you talk to. In Silicon Valley these days, a Youtube marketing influencer is in "tech", but a person who designs and builds particle accelerators is not. Go figure.
I also made a few Debian box like 15 years ago for a nonprofit I interned with. Seemed to work just fine for basic web stuff.
Android you excluded but its single handedly responsible for linux being the main way consumers access the internet now.
The year of the linux desktop is already here. The year of the FOSS desktop is a long time off.
I'm going to hazard a guess and say that the Amazon Echo* devices probably run Linux too.
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