You're misinterpreting Einstein. What he actually illustrated is that time is an illusion. Spacetime has nothing to do with time, rather it describes, among other things, the illussion of time which is perceived in measurements of state changes resulting from a magnitude of entropy whose variance is determined velocity and/or gravity, or comparable forces, which are not space constants.

For example....Einstein did not claim Person 1 and Person 2 could meet at a coordinate of space and time as you state. That's the exact opposite of what he said, which is that Person 1 and Person 2 CANNOT meet at a coordinate of space and time because that point of existence is relative to Persons 1 and 2 making this an implausible goal to ever achieve. it can be approximated within a tolerance, but only when these persons exist in the same relative frame, otherwise they could be at the exact same place at the exact same time, but 1000 years displaced, notwithstanding their individual perception of identical points in space and time.

He uses "time" to explain many things so that they are easier to understand, but make no mistake, he clearly shows time as something that does not exist and has explicitly stated that time, "the distinction between past, present and future", is nothing more than a "stubbornly persistent illusion".