An exam has always rested on a quiet assumption: that the person who wrote the paper is the person whose name is on it. In a hall, an invigilator settled that simply by being present. Remote assessment removed the invigilator and left a video window in their place.
A window is easy to work around. A candidate can be coached from just outside the frame, replaced part way through by somebody who knows the subject better, or helped by material on a second screen the camera never sees. Later the certificate itself becomes the target, because a qualification is trusted by employers and universities who have no practical way to check it.
The checks below confirm the candidate through the assessment rather than only at the start, and give a qualification something anybody can verify. Every finding goes to a member of staff to review, because an academic decision belongs to your institution and never to software.