The way you do online exams is by contracting other universities proctored test centers and making students attend the nearest one on exam day.
There's a whole system for this, it already works very well if people actually wanted to make online exams work. Of course it's not "social distancing" so it didn't help with covid.
For what it's worth I've tried that (here in WA state, in the US) and most colleges (including mine) don't have a test proctoring center. Occasionally you'll find one but the center will frequently will only proctor tests for their own college (i.e., it's not public service - it's just for that college).
So here in WA, USA there's definitely a system for this. If you don't mind sharing - where do you live? Have you used this proctoring-for-other-colleges system? How do you know about it?
People often say Virginia has a lot of good universities and I always thought they were overstating it. Maybe they're right.
Both the University I attended and the ones near my home town proctored tests for the public. I actually used that service very heavily in high school to test out of ~50 hours of gened classes.