I think you are missing the whole point.
That is exactly what I am saying. Currently there are technical limitations to the time measurement.
It seems you are thinking at this from today’s perspective, which is not the point.
If there was no such technical problem, it would serve as a perfect sequence order tool for anything on earth. If you had a timestamp, you would simply know the order, without needing to have seen the order.
And if you had that, then requiring to see the event order would be more complicated, and because of that, there would have been no reason not to use it (this other new shiny sequence tool, exact time).
You can read my post again, I say that you could conceive of such technical advances being made (implicitly: within not too distant future, otherwise it is just theoretical).