I'm not against it. But it's usually not more energy efficient. Life Cycle Analysis takes all the inefficiencies you mention into account, down to the zip code, and includes thing like present and future mix of electrical generation.

Doing it because China is, isn't really a reason.

You can take into account electrifying rail, but it doesn't really change much. This all gets taken into account.

>other efficiency loss in between.

The grid has plenty of inefficiencies, especially if we have to start designing beyond capacity to account for intermittent sources. But electricity's main inefficiency is in its creation.

LCAs take all of this into account. It's the whole purpose of doing one. Embedded energy involved in manufacture, refining, transport, everything, is all added up based on things like location and present and/or future inputs.

One of the reasons why China built such a network so fast is the top-down structure of the state. If the authorities decide to build something just across your neighbourhood, you are in no position to challenge them.

Although I like trains, I wouldn't want to live in such society.