Spacetime is about the behavior of matter. It has nothing to do with space or time. Spacetime is a tool.

Envision a tape measure. It is very accurate and can measure how tall you are. But it will not be involved with how tall you ended up being. Anyone saying that the tape measure is an actual part of how life exists is wagging a conceptual dog.

Clocks sent into space do not show us that time dilates. With Einstein, we can say that the matter of even the most stable material in the universe shows us a difference in behavior when placed in a different spatial framework.

In other words, the material the clock is made of changed its behavior, and the time display showed us that result.

If we are saying that time dilated, then we are wagging a conceptual dog. It was matter that changed.