SF’s Market Street subway runs on Reagan-era floppy disks

That was my thought too --- and given the deteriorating skills that even malware programmers today have been affected by, fitting it on a floppy might be a challenge itself.

If the problem is that the system is just that old, and that's the only criticism, that sounds like it's a near-perfect-for-the-job system that's firmly at the bottom of the bathtub curve¹.

Electronics of the era can plausibly continue almost indefinitely: plenty of industrial and aeronautical equipment does, as well as things like the tank-like HP printers.

¹: if it's coming up the other side of the bathtub and failures across the system are accelerating, then they should watch out.

They cannot risk running two trains on the same track so they suspend the rail system whenever an international train is passing.

My country managed to invent a new train signalization, whatsapp and radio signalization.

We experience frequent train crashes and delays because of this. Don't take any technology for granted, corruption can make it cost more, take longer and make it more dangerous.

There will be a point where operating the current system will become more costly (due to failures and outages) than developing and validating a new one. At that point it's rational to start replacing it.

It's not obvious, or even necessary, that there couldn't be sharing of domain knowledge between organizations so closely headquartered.

Maybe an example that makes the distinction obvious: Bill Gates can outfit his bathroom with all kinds of advanced tech, spending millions of dollars on it, and nobody will feel the need to criticise him for it. After all, it is his money and he is free to do whatever with it. However, if a city government builds a public bathroom that costs millions of dollars per stall, that's a scandal. You cannot take the same liberties with public money as you can with yours.