Jeff Carlson puts a number of webcams through their paces, including the models tipped by recommendation sites, and demonstrates that all of them—even an expensive Logitech model that costs $200—look worse than even the front-facing webcam on a 7-year-old iPhone. They're all terrible.
Uneven color. Blown highlights. Smudgy detail, especially in low light. Any affordable webcam (even at the high end of affordability, $100+), uses inadequate and typically years-old hardware backed by mediocre software that literally makes you look bad. You might not notice this if you're using video software that makes your own image small, but it will be obvious to other people on the call.
Matters won't change for reasons that are hard to pin down, but the pandemic was an obvious driver of demand. We can just hook up our nice mirrorless cameras and DSLRs, too, meaning the hypothetical market for high-end webcams is saturated with gadgets we already have.
That brings us to the other factor keeping webcam innovation restrained: manufacturers aren't as invested in what has been a low margin business catering to a relatively small niche of customers. Apple's research and development budget over six months is more than Logitech's gross yearly revenue, because Apple realized that the iPhone's camera could be a serious competitive advantage.
Wirecutter recommending the Logitech C920 (top right in the collage above) is particularly astounding. "Superb image quality" indeed. Carlson has a better tip!