Startups can outcompete the Foundational Model companies by concentrating on creating a very domain specific model, and providing support and services that comes out of having expertise in that specific domain.
This is why OpenAI chose to co-invest in Cybersecurity startups with Menlo Ventures in 2022 instead of building their own dedicated cybersecurity vertical, because a partnership driven growth model nets the most profit with the least resources expended when trying to expand your TAM into a new and very competitive market like Cybersecurity.
This is the same reason why hyperscalers like Microsoft, Amazon, and Google themselves have ownership stakes in the foundational model companies like Anthropic, OpenAI, etc because at Hyperscalers size and revenue, Foundational Models are just a feature (an important feature, but a feature nontheless).
Foundational Models are a good first start, but are not 100% perfect in a number of fields and usecases. Ime, tooling built with these models are often used to cut down on headcount by 30-50% for the team using it to solve a specific problem. And this is why domain specific startups still thrive - sales, support, services, etc will still need to be tailored for buyers.