This is absolutely not true.

I worked with a guy who used a DSLR as a webcam and his picture was totally remarkable over Google Meet and Zoom. The very first thing I did was send a screenshot of the meeting's tile view to a friend, asking if he noticed anything funny about one of the videos, and he easily spotted the one I was talking about.

Every time we had a new team member join the calls, they would immediately comment on this guy's ridiculously nice picture quality and ask him what kind of camera he had.