This is only one outsiders view and hold no weight but I went to several Masses with my friend when young. As I had not been raised or educated in Latin or the Mass, it made no sense to me. It was pretty, even beautiful at times but I understood nothing.
Fast forward many years, I went to Mass a few months ago and at least understood everything being said. It was still pretty and beautiful from my perspective but I also understood it.
I think there were most likely Catholics that were happy to finally understand the words and those that didn’t feel they needed to. Probably some understood the Latin having been trained. If some really left ONLY because there was no more Latin, then there were probably some that stayed for the same reason. Personal tastes in humans come in wide varieties and generalities seldom work.
As far as bringing in outsiders, a Mass that is completely non understandable isn’t going to work. If that’s not one of the goals, it doesn’t matter. If it is one of the goals, Latin isn’t a good tool.