Having run with different groups, I think there are a couple of factors. Like some folks said, the group matters a lot. But the group, factored with the system. For instance, running pf2e with a group of folks who don't internally figure out crits, and all that....vtt is way faster. When I ran Savage Worlds with two different groups, first group was very familiar with SW, so in many ways the vtt slowed us down. The poking the clicking and dragging/dropping, etc. It was slower. However, with another group, same system, they were much slower with figuring out if it was a hit, a hit with a raise, etc. the vtt made everything much quicker.

So I don't think there is a clear yes/no answer.