It doesn’t help that the Uniform Plumbing Code only recently added traditional wet venting to the code, although the name was changed to horizontal wet venting.
I collect old plumbing codes. The oldest plumbing code I have dates back to 1913. Of course, you have to realize that by 1920, less than 1% of homes had indoor plumbing. Hence, plumbing regulations were a new concept.
My cousin gave me a copy of a local plumbing code in New Jersey dating back to the 1920s. The small pamphlet is only 37 pages long. However, when you read the venting section, you find the precursor of wet venting. That wasn’t what it was called, but the installation requirement is what we call wet venting today.