These days with super accurate GPS, everyone is very close laterally. However, with super accurate altimeters the 1000 foot vertical clearance in RVSM air space is more than adequate. It just looks close because you don’t see it all the time. In the flight deck we see that 1000 kt closure rate all the time.
I knew I could get informed opinions in here!
Ah, finally on my last leg home...long day!
The altimeters in the small planes I have flown are only accurate if you have set it to the current barometric pressure.