Pre-cast track sections instead of ties/ballast

The NYC subway, and surely plenty of other transit systems, uses pre-cast "floors" to which rails are attached, instead of using ties and ballast as a base for track. I assume that the reason is that it's tough to maintain ties and ballast in tight areas, and I also assume that regular (i.e., non-subway) railroads haven't adopted this approach due to its higher cost.

Am I correct? If not, why don't regular railroads use pre-cast "floors" and attach rails to them? Wouldn't the rails shift less if they're attached to pre-cast "floors", reducing track maintenance and derailment costs?

A photo (from the E line at Archer Avenue/Sutphin Boulevard/JFK Airport) is attached. It's upside-down for some reason, but you can see the pre-cast floors and the rails attached to them.

Thanks.

Those are not precast. That is direct-fixation. The slab and plinths for the rail plates are cast-in-place. Requires very tight alignment and tolerances. Most of NYCT uses the cut sections of ties cast into concrete. A very quick installation that lends itself to night trackwork.