You're describing this setup like it's a choice between complicating someone's life or giving them a simple browser that just works. Phishing attacks are nasty. No matter what choice you make, a new user is going to have a complicated element they need to be educated about. You either have to teach them to use an adblocker, or you need to teach them Internet security best practices.
To jump back to the same comparison I made earlier, this is like wiring a house without circuit breakers because the owner is too scared to mess with the little switches. Is it simpler? Sure, but it stops being simpler when their house burns down.
Nontechnical users click on things; they particularly click on flashing banners that tell them they've won prizes, and they particularly click on images with scary fonts that tell them that their Facebook has the virus and needs to be updated. If you're going to give a nontechnical user a browser without an adblocker, you need some kind of other defense against phishing attacks, fake download links, cryptocurrency miners, and compromised Ads/CDNs that scrape credentials out of payment forms.
Do you have an alternative defense? If not, then I really feel like for someone as tech-illiterate as you're describing, giving them a bare browser is roughly the equivalent of throwing them naked into a hostile environment.
Disabling uBlock Origin is literally two clicks. I understand someone not knowing how to do that -- I don't understand not being able to explain how to do it.
And even in the crazy case where someone drops a course, that's still a preferable scenario to me over helping an Uncle remove a keylogger because a big scary box told him to click it on it.
When I set up a computer for someone I either need to teach them how to whitelist a site, or I need to teach them Internet security, which is not always possible to do. I think it's irresponsible to put someone online who's not an expert without at least some protection to keep them safe.
Imagine if this was the early Windows XP days, and someone was saying, "don't install virus protection or anti-malware on a Windows box, because some programs will be falsely flagged." Yes, sometimes safety valves trigger prematurely or block things they're not supposed to. That doesn't mean inexperienced electricians should remove all of their fuse protectors.
And the risks of breakage here are honestly really minimal. If a student taking an online courseware site notices breakage, 9/10 times they'll call up the person that set up their program and ask for help, and then that person will explain over the phone how to whitelist that one specific site. Or worst case scenario they'll file a support ticket and the support person will explain how to do that. They're not going to just say, "well, I guess I fail" and drop out of school.
DO be that expert. We should be practicing an ounce of protection. It is far easier to prevent viruses and phishing attacks for a nontechnical user than it is to recover from them. I firmly believe that anyone who can't be taught how to disable an adblocker should not be allowed to browse the web without one.