It's saving me time (sometimes 2x speed up on certain, well-specified, tasks), and I enjoy using it. I wrote a blog post with some details on how it has helped me code the database: https://www.philipotoole.com/what-did-gpt-4-find-wrong-with-...
That said, the most recent release of GPT-4 seems a little more buggy[2].
Simple as that. Of course, sometimes I got the "message too big" error. So I pasted bits of the sources files, choosing pieces I thought were reasonably self-contained. I also fed much of my unit tests through it, asking "see any missing test cases?" While some of the answers were not that helpful, digesting the feedback from GPT-4 made me think more about my code, and make some changes for the better.
Right now Sam Altman is channeling Zuckaberg by claiming to be the good guy changing the world, but in reality hoarding data and asking congress to build him a moat.