It really makes a better picture. Zoom / Meet / Teams / etc does compress a ton, but a big part of the horrendous video quality are webcams.
Another, potentially cheaper way to replace a webcam is to use the main (rear) camera of an old cell phone.
Digital photography, especially using tiny sensors, is computational photography. Webcams are too cheap to have reasonable processing power internally and webcam companies don’t have the budget to create high quality post processing software for the host computer.
Shallow depth of field also means that the video codec only has to concentrate on encoding detail in the [narrow] focal plane. In my experience, the results are stunning (50mm f/1.2L @f/2.0 and diffused LED video lights), and the combination of the well-lit in-focus elements in the image (transmitted by good glass) with the deeply and naturally blurred background would suggest that increasing the number of pixels in the image from ~ 1024x640 to ~ 1920x1080 would probably be far less noticeable than the numbers might suggest.
There’s a bunch of advantages even with bad video from meet or zoom.
Big sensor + nicer fast lenses means you require a lot less light. Nice fast glass means you can blur out the background optically without all the artefacts introduced by software background removal. If you use a zoom lens, you have a tonne of control over the framing.
I feed it into OBS and can get 1080p easily on a 5D MKII, a camera that's now more than 15 years old. Better quality than any dedicated webcam I've seen.
I thought you needed a 5DmkIII to get 1080p, because the 5DmkII has USB2.0 and is limited to a 200Mbps transfer speed (using MJPEG). And the HDMI resolution is much lower than that.
