I think we're probably still far from the full potential of LLMs, but I don't see any obstacles to developing and switching to something better.
We had plenty of options for better technologies both available and in planning, 56k modems were just the cost effective/lowest common denominator of their era.
It's not nearly as clear that we have some sort of proven, workable ideas for where to go beyond LLMs.
That's simply not true. Modems were basically the same tech in the dsl era, and using light instead of electricity is a very gradual refinement.
> we're probably still far from the full potential of LLMs
Then how come the returns are so extremely diminishing?
> I don't see any obstacles to developing and switching to something better.
The obstacle is that it needs to be invented. There was nothing stopping newton from discovering relativity either. We simply have no idea what the road forward even looks like.