Seems like there can never be good enough models; the user will want it up-to-date models with respect to news and culture.

For some uses, sure. But for plenty of uses that can be provided in context, RAG, or via tool use, or doesn't matter.

Even for the uses where it does matter, unless providers get squeezed down to zero margin, it's not that new models will never happen, but that the speed at which they can afford to produce large new models will slow.