Electricity price differences throughout the USA[1] are much more than 5%, so a 5% loss does not (in itself) seem to make long distance transmission uneconomical.
[1] https://www.energybot.com/electricity-rates-by-state.html
The percentage losses are irrelevant, except in the context of substitutes. An ICE could be 1% efficient if the next best substitute cost 100x more to operate. Likewise, 5% losses in transmission might add up over very long distances to mean that it makes more sense to build wind in the appalachians or off-shore from NY than it does to power the NE with solar installs in Arizona. OR, beaming energy eating 50% while costing even more due to the amount of exotic materials in construction.