In Eurasia railway companies often run fibre because they already have rights to the tracks. More importantly, one stop from a central station is basically city centre with high population density.

So? We have fully developed fiber networks everywhere in EU, but the last 500m ... 200m to every building is expensive (this about tree structures).

But it's less expensive per subscriber (and therefore more profitable and more expected to be delivered) when you have higher pop density.

It only looks to you like less expensive. Opening a street inner city and put something in the ground gets more and more expensive (think factors) the higher the building density and 'other things in the ground' get.

I recommend to start a business if YOU know how to keep the investment down.

This is really not some controversial discovery. Providers already know this and take full advantage. It's common for multi-tenants buildings to be wired by 2-3 ISPs and even nearby single family housing to have only one with serious installation costs on top.

Barring regulatory failure, providers don't even need to "open a street" precisely because of the other installations that already exist where wires can be run alongside.

>What impact should the central station have?

It would be a major destination, so one would expect fast cables to be laid out there (and be available in the close area). That's the case with important areas where I live at least.