I watched multiple fiber companies implode and my friends laid off in that time period. It was not a lack of demand but the unrealized not properly studied cost of digging in cities and associated time delays and extra costs and extra extra unforeseen costs by companies new on the scene. Some were warned by telco and warnings were ignored, funding was obtained by greedy short sighted people. This was in medium to large cities where there was already a significant footprint of other infrastructure that prevented trenching in new fiber and cross many different boundaries.
I can't really answer your question about AI.