My guess is it isnt, these systems are hard to trust, and the rhetoric "were aiming for AGI" suggests to me that they know this and AGI might be the only surefire way out.
If you tried to replace all of a devs duties with current LLMs it would be a disaster, making sense of all that info requires focus and background thinking processes simulataneously which i dont believe we have yet.
Overall a chatbot like GPT-4 may be useful, but not that useful as it stands.
If you can write well, it's not really going to improve your writing. Granted, you can automate a few tasks, but it does not give you 10X or even 2X improvement as sometimes advertised.
It might be useful here and there for coding, but it's not reliable.