

TL;DR - Because people are stupid.
One of my coworkers (older guy) tends to click on things without thinking. He’s been through multiple cyber security training courses, and has even been written up for opening multiple obvious phishing emails.
People like that are why company-owned laptops are locked down with group policy and other security measures.
An immutable distro would be ideal for this kind of thing. ChromeOS (an immutable distro example) can be centrally managed, but the caveat with ChromeOS in particular is that it’s management can only go through Google via their enterprise Google Workspace suite.
But as a concept, this shows that it’s doable.