I don't know, I used to work for a trainer who used the "punctures are like scraped knees" argument for letting dogs work things out between themselves. I believed it and preached it for years.
But the way I see it now, a puncture is like scraped knee - that my kid got because some other kid pushed him down. Not that he got because he was running and tripped.
I don't consider it good socialization for my dogs to have to deal with pushy dogs by defending their own space. Or to have to be on the defense because there are strange dogs about. Meg's dog reactivity has dropped immensely since I stopped expecting her to deal with such things, and Gusto, who has never in his life been put in a position where he had to be defensive, has some of the best dog skills I've ever seen in a dog. He will play with anyone, and is an expert at eliciting play from dogs who are nervous, but he never, ever runs up to a dog and pushes into their space.
It is easy for me to text a friend and say "hey, my dogs need to burn off some steam, want to meet at the fairgrounds/school?" and let them play with a couple of dogs I know very well, and whose owner has similar expectations for her dogs' behavior. Or to go for a 20 minute off leash hike in a field. I'm also happy to go for a 2 or 3 hour off leash hike in the woods a couple of times a week, which I realize isn't for everyone.
I know dog parks work great for some people, but I'd never recommend them. I don't blame trainers for saying the same thing. Most people don't have the skills to read dogs and know when they need to get their dog out of there, so they learn by trial and error.
Like I said, I get that they work for some people and their dogs. And I also understand (and am jealous) that dog parks mean different things for different people. Here, it's the acre or two of fenced in open space. I've seen pictures of "dog parks" on this board that are huge hiking areas.