This sort of thing drives me crazy because it just needs someone to ask the question "Why is this necessary?"[0]

The reality is that a sufficiently motivated cheat will cheat and will more than likely get away with it regardless of counter-measures when there's not a proctor watching over their shoulder[1]. If the goal is to test proficiency, there has to be better ways that work remotely.

Back in High School, "open book" tests were common in my Chemistry and Physics classes. The "open book" rule wasn't to help over privileged kids pass the test -- these were among the hardest tests; the book was useful only for referring to the myriad of formulas which a High School student was not expected to commit to memory, but if you were relying on that reference to tell you exactly what you needed to do to solve the problem, forget it.

This, obviously, falls apart in many contexts -- "open internet" tests are difficult to write in many subjects, simply because there are tools designed to answer those questions, immediately[2], but it likely just requires a little creativity.

From my own personal experience: I ended up taking a certification exam which was offered online due to COVID. They attempted to re-create the security of "testing in a center" by spyware and procedure (photographing the room from every angle, myself, my drivers license), all trivial to defeat if I was so motivated -- the procedure was even communicated in advance. And it was a certification for writing software[3].

I took practice tests, online, which turned out to be nearly word-for-word what I saw on the test. I knew the answers, anyway, but had I wanted to, I could have spent my entire study time memorizing the test answers -- not technically cheating, but the test has abjectly failed to indicate anything about my expertise. A more useful approach would have been to present me with a program utilizing the features that they wished to test me on, then present a set of multiple choice questions asking questions about that code. With a diversity of test programs and frequent changes, it would reduce the probability that a Google search would yield an immediate answer, testing the candidates ability to solve the problem using all of the tools that are available in the field.

Assuming that "testing is still the most reasonable way to assess skill", which is another argument in itself that falls victim to footnote "0", the point is to make irrelevant the forms of cheating that the spyware is attempting to prevent. Both are losing battles against cheating, but the former is less so, and certainly less consumer-hostile.

[0] The classic "Why do we do this?" with the most common answer being "Because that's what we've always done"

[1] Just off the top of my head, a small camera in the room aimed at the screen and a discrete -- in-ear, like my daughter's (Bluetooth) hearing aids -- ear-phone Bluetooth connected to a mobile phone to a third party in another room with a computer being used to research answers.

[2] And in a lot of contexts it still doesn't matter. If there's a tool that changes how that question is solved, and you're testing whether or not someone can solve that specific problem -- not whether or not that somebody can write a tool to solve that problem -- wouldn't it be more intelligent if they solved it using the most appropriate tool?

[3] Before I get grief; it was requested that I take it out of the expectation that I would require no study and was needed due to us being a MS Certificate Professional shop.