no, that's trivially refuted by considering the simpler but still consistent explanation that video calls are employed to more closely mimic the contemporaneously rare in-person meetings without considering (negative) utility at all.
in any case, your argument is circular because you're implicitly asserting utility must exist ('if they use video, it must have utility'), and then pointing to that just-asserted utility as (unsupported) refutation.
It doesn’t matter what the video calls are used for - the claim was they have less utility than phone calls. I suspect you are over thinking this. People choose video over phone only sometimes because it has more utility for them - hence the hypothesis is false. Simple.
in any case, your argument is circular because you're implicitly asserting utility must exist ('if they use video, it must have utility'), and then pointing to that just-asserted utility as (unsupported) refutation.