These are all very good points, and there is in value of having a common framework for front-end development. However, I would argue React isn't always the right tool for the job, yet it has become the dominant framework, and that dominance is being further bolstered because of generative AI.

This isn’t about React being the best tool or that it’s Model is good for LLMs (I don’t see any evidence there at all). It’s about React being past the point where network effects make alternatives viable.

So even if a better framework came along, and ideally one that's not owned by Meta, it would be very difficult for it to take hold because of this.