I don't know, but I've often thought that without a universe-with-contents, without movement or change, time does seem meaningless. Perhaps, just as motion needs time, time also needs motion? I've also heard a "cosmic switchback" theory that says that some time in the far future when all we have is homogenous pea soup (the "heat death of the universe"), the whole process will go into reverse, including time, until we have another enormous bomb which will start another Big Bang, and so on ad infinitum. But that all seems to me to presuppose another kind of time by which the cycles of the switchback could be measured. Maybe these matters are too far outside of normal human experience to think about?
Anyway, I still don't quite get how time can be just a fourth dimension like the 3 dimensions of space. It seems to have a very different quality to the space dimensions.