I think I'm missing your point. I'm under the impression that electricity has never been easy or cheap to move very far, and it's not clear to me how solar-generated electricity is different in that respect.

You're mixing up two different things. Moving electricity with HVDC is easy and cheap... building the grid infrastructure is, well, not so easy or cheap.

The system cost depends on connection queues, transmission buildout, substations, transformers, planning permission, curtailment, etc.

Production of transformers, cables, and labour capacity are bottlenecks. Planning is a bottleneck.