I don't know how much IT experience you have, but at the end of the day when an organization pays for license, they're paying for a fall-guy. They want to have someone to go to when there's a problem with the software, because that's cheaper than everyone needing to hire an expert at whatever issues pop up to be certain it's solved.
They don't want to have a bunch of PCs running whatever distro and domain software the last IT guy felt like going with. And when the next heartbleed/shell shock/spectre happens, they don't want to have to figure out how to get the fix for the flavors of software they went with. They want to be able to say "hey company, this is what we pay you for" and the company to say "all good, we got you".
Of course, it is possible to have both open software, and corporate support. This is why redhat exists. Just understand that your IT dept may have a preference based purely on how easy/hard it makes their job. When my PC has some bug or hw incompatibility, I'm willing to take the time to solve it. But someone who doesn't have that time is going to prefer to just tell the company that made it to solve it.
I'm also on-board with no computers in schools, as someone else brought up. Phones should not be allowed in classrooms. Before we had LLMs running on calculators, my idea was to have a series of optional classes where you build your own calculator starting from logic gates, and that's the only computer you're allowed to use.