Not entirely relevant to this debate but related and interesting (well, to me anyhow) is how some aspects of measurement & positioning are very precise.
Many years ago, as part of my vocation training I had need to understand surveying techniques, which I found really interesting and totally practical:- you knew if you were right because certain things were proven.
Anyhow, what I am getting to is that within a short while after the basics you learn how to make certain corrections within your calculations and one of these is an allowance for the curvature of the earth.
You may think that on a local level it isn't discernible, but I can assure you it is.
I know of an instance where a major survey at an airport for a runway extension had been undertaken and they were having all sorts of problems with the results. A friend of mine, of the old school, was sent to troubleshoot.
Despite protestations to the contrary 'that of course they had allowed a curvature correction' the autopsy proved otherwise ! My friend was vindicated as it was his first hunch that the amount of error indicated no such allowance had been included.
By the way, the learning of this was the manual way and didn't include any GPS technology (mainly because it didn't exist at the time !!)
So whether it is a building, a football pitch an airfield or the Everest range - it is 'certainly something worth knowing'.
But, despite professional accuracy - I agree with Mel, keep it simple. You don't need to know how to perform a lobotomy to cure a headache