I understand the point made, but I’m conflicted with the clock example. We make the assumption that the clock measures time, but this only stands true as long as time and the action the clock repeats to measure it remains “in sync”.

Imagine you set two sand clocks and you let one fall vertically from a tall building roof. If you compare the two clocks after the fall, the one on the roof will be ahead of the one you throw. Looking at this, someone might wrongly conclude that the fall slowed the passage of time when, in reality, it was just that the device used to measure was no longer able to be representative of time passage.

I’m not trying to be a smartass here, I’m sure there is plenty of fundaments to not doubt the premise that speed slows time, I’m just trying to wrap my head around whether the light clock example talks about time slowing down or our inability to measure it.