I think we'll start to see a differentiation soon. The likes of Ilya will raise money to do whatever, including foundation models / new arch, while other startups will focus on post-training, scaling inference, domain adaptation and so on.
I don't think the idea of general foundational model from scratch is a good path for startups anymore. We're already seeing specialised verticals (cursor, codeium, both at ~100-200m funding rounds) and they're both focused on specific domains, not generalist. There's probably enough "foundation" models out there to start working on post-training stuff already, no need to reinvent the wheel.