A big potential advantage of these kinds of solutions is that you can just site the plant such that you can avoid building the transmission at all. Of course, nuclear obviously has its own NIMBY concerns, permitting issues, etc., so it's not a panacea.
An other comment here talked about how almost 80% of the energy bill in California are from fixed costs from primarily transmission. That is a lot of space to create economical incentive for people to have a plant located very near where they live. Similar, politicians are much more willing to be permissive with permits when there is an economical benefit for the region, as energy costs are quite significant bit of a regional budget.
You are fighting two separate forces. Some of the energy is lost to heat in the wires, this is minimized by making the voltage as high as possible--but the higher the voltage the more corona loss there will be.
I forgot most of the details, but iirc the losses can be up to 33% in certain conditions (mostly cold weather).
I recall however that I read about a blue halo forming around some cables in snowy nights as electricity charges the air surrounding said cables.
This phenomenon was a huge source of losses in transport cables.