LLMs by their very nature subsume software products (and services). LLM vendors are actually quite restrained - the models are close to being able to destroy the entire software industry (and I believe they will, eventually). However, at the moment, it's much more convenient to let the status quo continue, and just milk the entire industry via paid APIs and subscriptions, rather than compete with it across the board. Not to mention, there are laws that would kick in at this point.
Surely they've reserved the best models for themselves and have people looking into how to optimally harness untapped potential from LLMs?
Edit: I guess the competition between them keeps them honest and forces them to release their best models so they don't lose face.