This is a very fair question! When I wrote this comment, I was definitely thinking of the "real" mainstream, i.e. users of llm chat to generate text, not software engineers.

But I think there is (and has always been) also a distinction between the "mainstream" of software developers vs people who are working on new tools and capabilities to be used by that "mainstream".

IMO it is certainly true that the most efficient and cost effective was to do "mainstream" software delivery at the moment is hosted frontier models. But for people thinking about "what's next?", it makes a ton of sense to be exploring different models in anticipation of a possible (but certainly not inevitable) sea change.