The reality is at BigCo there's always that one part or another part of the company that's fine to work at. There are a whole lot of other parts that are not. The trick is to find out what the good parts are and avoid the bad ones.
I 100% agree with you. It's a gigantic company. As far as I can tell (finger to the wind), my team is in the 90th+ percentile in terms of experience and maturity. I feel very lucky to work with the people I do, I've learned a lot from them.
When we start talking about the distribution of experiences of hundreds of thousands of people over a decade, we should expect a very long positive and negative tail. I expect that if I were rehired, my experience would regress to a mean worse than what I currently have.
Maybe you just got lucky.