Route Offset
 

Given the accuracy of GPS equipped a/c, why isn't a random offset built into into the system for en-route operation when flying in RVSM and other airspace?

I did hear that in Africa, pilots will rte offset using the FMC "just in case".

Visiting the cockpit once of a 744, I could clearly see on the EFIS display that the commander was flying an offset, but didn't ask him why.

Wouldn't a random minor offset built in, and non-adjustable by the pilot help minimise mid airs?

I was just thinking about the 757 and Tu-154 collision, and possible ways it could have been avoided.

Yes system accuracy can be a danger in this case!
An inbuilt offset of just .1NM to the right for everybody would be a great help.
I used to do that, then gave up due to laziness...
But it's certainly a good idea, not only in Africa.