It would be surprising if all publicly available vaccines had "overwhelming" evidence in support of their use. That would seem to imply that our public health system hadn't yet approached diminishing returns in searching for things against which to vaccinate, and that large gains were still to be had by vaccinating against more diseases.

What makes you think this (your second sentence) is not the case? Plenty of devastating diseases still cannot be prevented by vaccines; that's why people continue to research and create new ones.

Whether all publicly available vaccines (or, more weakly but more relevantly, all recommended vaccines for a particular individual) are worth getting is a separate question, but the recommendations are evidence-based, and I personally believe they represent a guess as good as I can make.