The big change: no more big universally used frameworks like React, Vue, etc.
Every company has its own little special framework crafted by an AI with its own nuances you need to learn, and your skills will no longer transfer from company to company. Gone will be the days when you can swap out a software engineer for a similar one with the same experience in a framework you use. Every engineer coming in has to start from zero and learn exactly how to work with your special paradigms, DSLs, etc.
The LLM only "knows" what's in its training corpus so it's output quality is going to be comparatively crappy on private custom frameworks with only a small codebase to train on (relative to the entire corpus). Companies with private frameworks will therefore lose out.
If anything, the opposite is going to happen: LLMs will cause consolidation and software evolution to grind to a halt. Coders are going to gravitate to libraries and frameworks the LLM generates the best outputs for, leaving a few big winners and the rest going extinct. New language features and new frameworks will be slow to enter general usage because of the chicken and egg problem: there will be little or code in the LLM training corpus that uses them idiomatically until some humans write enough quality code using the new features/frameworks that can be absorbed into the corpus to meaningfully affect its output.
Except no companies will allow substantial improvements to enter the public corpus, because they will basically be giving away their competitive advantages that will quickly be gobbled up by other LLMs. Those improvements will represent larger investments since there will be fewer engineers who can write them by hand.
Every company has its own little special framework crafted by an AI with its own nuances you need to learn, and your skills will no longer transfer from company to company. Gone will be the days when you can swap out a software engineer for a similar one with the same experience in a framework you use. Every engineer coming in has to start from zero and learn exactly how to work with your special paradigms, DSLs, etc.