Here's a question: why do people care so much about what they look like or how the camera displays them? Personally, I care more about the content being delivered than what someone (including the scene) looks like.
IMO, we all want to believe that but we really don't. All other things being equal, a professional-looking setup will trump someone streaming from their messy bedroom unless the content is really that good, which it typically isn't. Conscious or not, first impressions are a thing.
This is the type of opinion that used to infuriate me as a young programmer, as I used to think that good code presented badly would win over bad code presented nicely. I can now admit that I was wrong, and I therefore always invest some time in making everything look as nice as possible. Making my delivery more professional has not shown any downsides yet.
I think we only notice quality setup on video calls now because that one person that cares stands out.
Google search has degraded so I can't find it, but I remember a couple years ago that a study showed people subconsciously associate image quality and lighting to status. People with better lighting look richer and of higher status.
It's unfortunate, but it's unsurprising.