I agree, software (software startups) has always been the golden child of investors because of how cheap it is compared to hardware or any other physical good.

Good software is expensive regardless of the involvement of LLMs because you need someone to take responsibility. Large companies will save a buck because there may be fewer people needed to take said responsibility, but it's probably a marginal saving compared to the overall scheme of things.

It was "easy" in the sense you could deploy 7B equivalent of a developer, who could get something sort of working eventually or you could spend a lot of money for actually getting the results from talented developers - equivalent of daily maxing out Opus 4.6.