I have worked in academia and I am aware of the restrictions on purchasing. But as an individual you can purchase software for yourself. You can encourage your students to purchase software. You can even make it a requirement of a course, in the same way as buying a textbook is.
I have never come across that is more reluctant to actually pay for the tools to do their job than devs. Hell we've even built a quasi religious cult in foss that revolves around not paying. Yes yes I know the "free" In foss is supposed to be free as in freedom, but in practice it ain't, it's all about free as in beer. See the gp and the offence taken at actually being asked to pay for the foundational tool they use to do their job.
Which (reputed) university will allow for a sysadmin to tell students that they need to purchase Ubuntu to attend a course? Seriously, the sysadmin will get fired (at the least). Given costs of education (at least US) asking someone to buy RHEL for about $300 would be PITA (for poor students). Most sysadmins are invisible. And at our University we have about 100 Debian servers. Do you mean if we move them to Ubuntu (I personally) buy so many licenses? Are you working for Canonical?
Both sides should calm down. It is OK to criticise Ubuntu/Debian/RHEL. A restaurant critic does not have a restaurant. CKS anyway says he/they will move to Debian.
It is not that any employee can just purchase things in academia (at least in 3 different countries I worked at). Most money and purchasing power, approvals go to official-administrators (even if Professors take efforts to apply and receive grants). Spending is highly regulated. There were times I was denied buying RHEL telling me to use a 'free linux'. There is a wide belief (among official-administrators) Linux is free so paying for it is the employee wasting money. To even encourage Dell's linux server offerings I once purchased a few preinstalled RHEL devices but was later asked why not use free ones (or the windows dell offerings as they were strangely cheaper - thanks to bloatware).
At the same if you say you need to buy a windows server or zoom license this will be approved as these people know that it is not free. Their society is conditioned in this way.
In the rare case if this was approved, usually there are external auditors that analyse spent money and come back at you for not using free linux.
Ideally Canonical and RedHat (via IBM) goes to these administrators (or meetings in Ministry of Education) and advise them that making software is $$.