Laying fiber that supports 200G literally costs exactly the same as fiber that supports 100M.
It’s just single mode fiber and when you have it you can run anything over it you want.
You can also add expensive DWDM equipment at both sides and run a multi Tbit line over it.
Also you can still use it in 25 years.
Building anything else than P2P fiber is just dumb.
Laying fiber that supports 200G literally costs exactly the same as fiber that supports 100M. It’s just single mode fiber and when you have it you can run anything over it you want. You can also add expensive DWDM equipment at both sides and run a multi Tbit line over it. Also you can still use it in 25 years.
Building anything else than P2P fiber is just dumb.