I went to The Iron Yard, their very first offering in Atlanta, back in 2014. My cohort was focused on full-stack development; it started with Ruby, Sinatra, and finally Rails.
I graduated that summer and immediately began doing contract work with a couple fellow graduates. By the end of 2014, I had moved my family to Chattanooga to work for a startup in the eSports space. It was a Rails shop and they had grand plans but the senior developer left and our CEO decided I could take the lead. To be blunt, I wasn't ready, obviously, and knew it. I wanted to be a part of a team and have room to make mistakes (plus be mentored); you can'd do that when you're the only developer then lead developer. So, by spring of 2015, I joined a wellness startup (awesome team) in town and have remained there ever since.
In the beginning, all I did was write tests. I started to contribute to features on both the front and back ends. Now, I own entire features, make design decisions (re: database, code, and the stack), implement CI/CD, review code, and randomly build things in other tech (like an iOS app for testing Firebase Cloud Messaging integration). There's no way I could have done much, if any, of this fresh out of bootcamp.
Bootcamp got my toes wet and taught me, beyond introductory full-stack concepts, both how to read documentation and to accept that programming is hard. Those two lessons are what really helped me to become a professional developer. My team accepted me because I was still passionate even after learning so much so fast. They also were confident that when presented with a problem I would either have a solution, know how to go find one, or be smart enough to ask for direction (that last one took more time to develop than the others).
To be fair, I was an intelligence analyst by trade prior to bootcamp, so I definitely had previously developed skills useful to programming. However, as others have said, bootcamp was/is a springboard that provides structure to the process.
As for my peers from the cohort, I think MAYBE half are still developers and a few own companies.