I've shot deer off the ground with a bow without a blind. My buddies consistently shoot deer from 10-15 feet BUT from my experience there are COUNTLESS benefits from hunting much higher.
Personally, I know I could kill deer at 12' for example but I know there would be many deer I never saw because they nailed me far before I saw them- never knew i busted them ( them getting me far off by scent, visual, etc).
If folks have good luck hunting from 6' OR they don't like heights- by all means, it's totally up to the hunter of course- OBVIOUSLY.
In my experience, I have no reason to hunt lower, I really have found few situations, trees, etc that I saw any benefit to going lower- in all cases I found countless benefits to getting up there (getting spotted - close up OR from distances, cover, scent, MOVEMENT while you're up there, better view, more effective on MATURE bucks, etc, etc.).
*OK- in all fairness, this is coming from the guy who fell 32' hanging one of these in July a few years ago and shattered my arm and broke my 7th vertabrae, etc.

Don't be an idiot and leave the harness at home that day!
I think I'll post these pics as a reminder to folks a couple times a year!
**IF you are SAFE, my strong preference is HIGH up there to this day though! Just don't be an idiot like me!