It's almost like in real life. What's wrong with damage from a height? In life, this also gives an advantage. It sounds kind of weird.
Why do people always come up with "it's realistic that height gives you advantage"?
This discussion happened so many times, and I absolutely despise this argument.
Can we please stick to say advantage in the usual sense and call the DnD 5e rule mechanic 'Advantage' something like DnD Advantage? It's less confusing.
And again i want to point out: Imagine you and I stand 10m apart and aim at euch other with a bow. With both are equally skilled. So we both have the same chance to hit, let's say 75%.
Now I get on a table, and I am 1m elevated above the ground. Nothing else has changed. Now suddenly I have a hit chance of 93.8% (DnD Advantage --> high ground) and you have a hit chance of 56.4% (DnD Disadvantage --> low ground).
Is that realistic? Because that's exactly what's in the game right now.
And, what adds, is that the one on high ground ALSO has the advantage (not DnD Advantage) of being on high ground and melee fighters will not reach you so easily.
It's just ower-powered, unrealistic and - most importantly - unavoidable, because we have a lot of verticality in the game (which is a good thing).
So it's just a very bad homebrew and it - imho - should go.