>>1789416True, but the city was still greatly centered around downtown Manhattan as the center of activity, while London doesn't have one single clear urban nucleus. For example, look at the position of the main railway termini: In New York you had Penn Station and Grand Central Terminal, which are pretty close by, and they were bordering the downtown which we can say stretched to the southern tip of Manhattan which was the industrial area.
In London you have Liverpool St. station on one side, Victoria Station on another, then Euston in the north, Waterloo in the south. It shows that the center was much more spread out, whcih makes sense for a city that had been one of the main capitals of the world since the time when New York was still New Amsterdam. otoh, as is generally common in Europe, the residential areas are denser and closer to the city, again as is usual for a city that grew before the railways and subways, while many of the residential areas in New York grew with the advent of the railway, when people could choose to live further away in less dense areas.
So tl;dr London has a spread out center and more compact residential areas around it, NY has a compact center and spread out residential areas. So London got a more grid-type system with no express services, while NY got a more radial-type system with express services.
Finally one more aspect I'd say was that the London underground was partly built very early so it would have been a hassle to dig it all up again to four track lines (impossible for the deep-level lines except with a whole new tunnel), while also there were lots of railway lines for suburban services, While New York only had a few railway corridors and built their subway comparatively late, so it made sense to build 3 and 4 track lines for suburban services.
