The "good enough" concept is interesting because of how systematically people over estimate it. So often, things that are lower quality but thought to be "good enough" turn out to be either not good enough or not worth it compared to just using the higher quality "thing".
I will believe that smaller models have hit that bar empirically when I see them in production. At the moment, even frontier models are stuck in most of the scenarios I am seeing for high value tasks at the "not good enough" gate - so small models are not even close to being on the scene there yet.