I’ve been in IT for over 20 years the most of the people who use Macs do so because there’s supported business software written for it while still being Unix under the hood.
I too been in IT for over 20 years and most people I’ve seen using Macs were Graphics Designers and Marketing types.
I’ve seen but a handfull of IT Professionals using them and I’ve seen significantly more IT Professionals using Linux for work than Macs.
My experience covers a couple of countries and various industries since I’ve worked as a contractor (a kind of Freelancer) for most of the time so moved around a lot more than people working as permanent employees would.
Maybe one or two people I’ve seen using Macs cared about it being Unix under the hood and I think all of those were the above mentioned IT Professionals who used Macs.
People doing Graphics Design and other such digital media work (which is how Marketing types commonly ended up using it) really loved them because they were easy to use, had proper color calibration together with really great quality high resolution screens (the first properly supported 4K computer screens were Mac), plus the whole Adobe Suite as well as pretty much all other top professional design and media work software has full native Mac versions. These people were, however, not computer experts in the IT Professional sense of the word (even the Graphics Designers working on Tech Startups were tech users, not tech experts) and did not at all value the “Unix under the hood” characteristic of Macs.
Mine was mainly at startups that did big data and open source software, and the only folks in the org who used Windows were generally the accountants.
Yeah, during my period in Tech Startups I did see a bit more of usage of Macs than in other places (such as Finance, Software Products, Software Consultancy and even Publishing), but always felt it was driven by the whole halo of “fashionability” around Apple Products, which isn’t really a rational reason.
In my experience Mac use is also more likely in people doing Frontend work than Server-side work, maybe because the latter is not at all about visuals and most server-side work targets Linux so it’s way simpler to just have Linux in your workstation.
Then again I’ve been using Linux since the 90s so maybe I’m biased ;)