> Similarly, a GPU manufacturer can open source their drivers because this won't prevent them from selling their hardware

I agree with your broader point, but GPU manufacturers can't, because then we'll see just how much is done in software which makes their cards better than their competitors, which means their competitors can adopt those software techniques in their drivers. Also the manufacturer may not have the rights to the code in the driver's to release them as open source.

Their product is the hardware but clearly without software the product has little value.

So they invest resources in building the software.

Another hardware company comes along. Their product I'd also hardware. The software they get with no investment at all.

The second company has a strategic advantage. Far fewer software development staff. No carried software investment to cover. Hence lower costs. Hence cheaper product.

In theory company 2 sells nothing because the buying public understand the models, and are prepared to pay a lot more for the same or lessor product.

In practice the buying public doesn't know about Open Source, and the tiny fraction that do, don't care enough to matter. Hence the success of iPhone and the lack of traction for the latest "OSS Phone".

I mean, in that case I'd see that as a company which makes its money in other ways, throwing their scraps at the open source public. (Which, let's be honest, has been greatly beneficial for the public - it's given us Kubernetes, TensorFlow, etc.) But I wouldn't call it a business model onto itself.