Sigh....
One thing you want to ask yourself is why, for sure, would a vet know what's best nutritionally when they only receive about 1.5 hours of nutritional education during their entire education? There are a FEW vets who will truly admit to the travesty of what vets really know about nutrition - and
here's one of them who is truthful.
Also, READ labels. You will see for yourself that some "Puppy Foods" have the exact same analysis as many "Adult Foods". For many others, the real differences are marginal or scant. For some, there are differences - but not necessarily bc they are Puppy or Adult, but perhaps bc they are grain free or not (or whatever).
The one you're feeding is 24% protein, 15% fat - a midrange food if I ever saw one - there is nothing radical, no red flags, nothing concerning there - in my opinion.
I would encourage you to
read this white paper and perhaps give it to your vet as well.