The evolution of AI has been interesting. Even during the rapid commercialization, companies have competed through development, marketing and applications, not patent lawsuits. Most models have similar architectures, and the difference is in the data and training.
Big companies are trying to differentiate through perceptions of scale (we trained with sooooo many GPUs, so no one can beat us) and money (e.g. pushing copyright maximalist arguments) and recruiting (e.g. we have the best engineers, so no one can beat us).
While it seems like there are many companies that are training models, most of the energy is on applications - few care to compete with big US companies on training models, and the impression has been that the future will be scaffolded by a few