PBS Space-Time getting back to it's fundamentals with a series of episodes about what is space and what is time?
Is space even a thing?
I'd say a cartesian coordinate grid is not a thing, it is a map overlaid on top of space.
But Einsteinian space is warped and bends, it's a structure. A field with slope and direction that can be mapped rather than being itself just a grid-map.
It's still just a map of a thing though, and that thing is more complex than the map. The characters in a computer game might think space in 2d and you might laugh and say "silly Mario, space is really 3d" but really Mario's space is a one dimensional RAM array with a 16 bit address index.
Space is a thing, but it might not be a thing that's very spacelike.