When I was an IC engineer, I learned a lot by reading pull requests. Like, a lot a lot, probably more than any other single source. But PRs have changed dramatically over the last couple of years. What used to be lovely, well-crafted stories have devolved into an arms race of which LLM can write the most number of words about what the code is doing (which btw, the code already tells you).
The PRs of old were glorious teaching tools. I learned about tradeoffs and the long windy road to solutions. I learned how to apply prior art and previous experience. I learned about baking off different solutions. I learned about failures and how to deal with them. I learned about icebergs. I learned discipline. I learned tricks that seemed like magic. I learned storytelling, socializing, and how to make a case. I myself learned how to teach using them. And I learned about my coworkers and how much I appreciated them. In short, I developed my style. They helped shape me into the engineer and manager that I am today.
There is a real art to writing thoughtful PR descriptions and code comments, and I would love nothing more than to see this style of teaching make a comeback.