You are equating the removal of a bonus for ranged attack from high ground, with removing combat tactics. You have nothing to support your opinion, other than "you believe that high ground should give "some bonus", while completely ignoring the inherent benefit of getting to high ground, less chance of a ranged character being pulled into melee, and greater chance of maintaining concentration spells.
Getting to high ground does not make a person more accurate with a ranged weapon.
How does high ground help maintain concentration?
Indirectly, of course. If people on low ground have disadvantage to attack = less chance to hit = more chance to maintain concentration.
True but don't forget surfaces.
Surfaces are the main issues related to concentration according to me and highground usually changes nothing.
Nearly every attacks against AC will miss due to disadvantage but surfaces will always hit. This include spells - (missing) arrows - (missing) potions.
Even when you're higher in the goblins camp (outside) ennemies are throwing such items or spells.
The only situation I remember during which I was "too high" (and "protected") was inside the goblins camp. Same about breaking the LoS. This is the only location I remember it was a valuable strategy.
In other situations ennemies can throw things, teleport, jump or easily move close enough. Usually you aren't covered enough to break the LoS or higher enough to be protected from ranged attacks/items.
