Sure, the AI _can_ code integrations, but it now has to maintain them, and might be tempted to modify them when it doesn't need to (leaky abstractions), adding cognitive load (in LLM parlance: "context pollution") and leading to worse results.
Batteries-included = AI and humans write less code, get more "headspace"/"free context" to focus on what "really matters".
As a very very heavy LLM user, I also notice that projects tend to be much easier for LLMs (and humans alike) to work on when they use opinionated well-established frameworks.
Nonetheless, I'm positive in a couple of years we'll have found a way for LLMs to be equally good, if not better, with other frameworks. I think we'll find mechanisms to have LLMs learn libraries and projects on the fly much better. I can imagine crazy scenarios where LLMs train smaller LLMs on project parts or libraries so they don't get context pollution but also don't need a full-retraining (or incredibly pricey inference). I can also think of a system in line with Anthropic's view of skills, where LLMs very intelligently switch their knowledge on or off. The technology isn't there yet, but we're moving FAST!
Love this era!!