Freight and passenger rail rail do not mix. Amtrak needs to build their own track instead of complaining
Within the Sydney metropolitan area, commuter trains are operating among freight trains at 5-15 minute frequencies, though with dedicated freight bypass lines in some places.
One issue in the USA, alongside private ownership of the rail lines, is oversized freight trains and resulting overbuilding required of passenger trains for crash safety. Unfortunately that rules out high-performance EMU designs as used in other countries. I believe Caltrain had to get an exemption for their ongoing electrification upgrades.
Where lines are constrained they can invest in parallel tracks and increase current capacity. Everybody could win in this way.
It’s hard to rank such systems but the US is a long way from #1. Being for example 113th in terms of miles of track per population.
In terms of efficiency we rank 31st in terms of miles of electrified track at a paltry 2,000km which significantly increases costs. https://en.wikipedia.org/wiki/List_of_countries_by_rail_tran...
Don’t get me wrong I have heard people say the US has the #1 rail network, but objectively I have never seen anyone actually back it up.
