That wheel has turned. The king of long distance transmission is now HVDC, to be point of sometimes being used intra-grid and not just for interconnects.
That is correct. When that will be available is the hard thing to guess.
There are currently enough production of electricity that is motor based (think about gas turbine, water turbines, etc), so there is a nice benefit of having AC at source and distribution.
The infrastructure needs to change. With an average lifetime of a substation in the 50-75years, it's hard to expect we'll overhaul completely the distribution system over night.
It's also hard for me to understand the power loss between the two scenarios (AC production, ac distribution, ac/dc conversion , dc consumption) and DC production, dc stepup to HVDC, dc distribution, DC stepdown and DC consumption). Even 1% at national scale means millions, so the entire business case might be anchored there.
I'm sure there are smarter people than me here that can cast some light on this
