> Anecdotally, I find engineers are way more prone to omitting the video feed and to lean on emails as response mechanism. I guess there's also a "people's person" vs "things person" thing going on.

To me, it's refusing to show up with a knife to a gun fight. The company needs a thing. The "things person" stands no chance in direct confrontation with a "people's person" and they know it, so they to avoid calls (direct or otherwise) to level the playing field. A "people's person" could fare much better against the seller's "people's persons", but then a "people's person" is in much worse position to understand the thing the company needs in the first place.

For buying things, a win-win outcome can occur only when people on both both buyer and seller side are "things persons".

It's basically a Prisoner's dilemma, with "people's person" and "things person" in place of "defect" and "cooperate".