Those [fast] trains are not comparable to cars, they’re comparable to airplanes. The metros and light rails that are intended to replace cars are overwhelmingly more efficient per potential passenger.
Local public transport needs about twice as much energy than high-speed trains.
Comparing a vehicle [train] that is usually run near capacity
The average capacity utilization is more like 20%. See the source above or https://www.zeit.de/mobilitaet/2019-02/nahverkehr-oepnv-bus-bahn-zahlen-preise-statistik
Every human being carrying around multiple tons of metal with them can’t possibly be efficient.
Explain to me how a train with 2 metric tonnes per passenger can be efficient?
None of these three links is behind a pay wall. (You have to accept the GDPR-banner thou.)