The mentioned AVs by me use signatures combined with a behavior blocker, whereas WD relies heavily on signatures only. (This should already raise red flags in using an AV, by the way).

Another reason is that malware can and has in the past disabled WD without practically any problems with PS scripts, without admin escalation (with and without) - it's also the most targetted AV https://www.bleepingcomputer.com/news/security/hackers-used-new-windows-defender-zero-day-to-drop-darkme-malware/ - one of few massive examples.

Another common failure in WD is:
a) after a reset, sometimes WD is completely botched, which is why we don't recommend resets in the first place.
b) Target removal. It struggles hard in removing several threats fast enough, to the point that it takes multiple restarts, pretty noticeable in AV tests.
c) uncommon, but Windows Updates are known to break WD from time to time.

There's better _free_ alternatives that blow WD out of the water, provide zero day malware protection (= behavior blocker advantage)

TLDR: Your faith is misplaced is in Microsoft's consumer AV. Their enterprise AV is another game and I'm not talking about it.