It's fair to be impatient, though I have no experience in making this kind of thing so I can't comment on the speed in which these VNs are being made. However, I think the stories they tell and the emotions they create are worthwhile enough.
It seems that all VN studios that create quality work take time, and burnout is a cruel maiden. As long as these stories are given the opportunity to be concluded, I don't mind waiting.
Hopefully you find a dev/dev-team that suits your pace, have a good one!