Imagine if you went to work at a bank in IT for example. They issue you a laptop.
Who is the owner of that device? The Bank.
Who is the owner of that network? The Bank.
So they are the arbiter of trust in that area. They are free to exclude non-bank-owned devices.
I work in IT, and I’m fine with getting a company laptop for company work. I don’t trust that laptop. I isolate it when I work at home. But the company trusts it, and that is fine.