I think AI models will evolve by generating synthetic data, filtering and improving it, and then retraining. Possibly with external systems in the loop - code execution, search, human, simulation or robot. Quality won't degrade because there will be a lot of effort put into data filtering and diversity. We can always improve on a model by giving it more time.
Model architecture doesn't matter compared to the dataset. Any model from a class can learn the same skills from the same data, but change the data and they all change their abilities - the intelligence is in the data.
The future is data engineering, not model architecturing.
Human culture, by analogy, evolves faster than human biology. The data is evolving faster than the model. And we are seeing a drastic reduction in novel architectures in AI, diverse datasets applied to the same transformer models in recent years. Even among the transformers, very few variants are largely used, thousands of them abandoned.
I like to think of it as language evolution by memetics being the real engine behind intelligence. We and AI are riding the language exponential together.