Cover is a very nice feature, like flanking reward tactical gameplay and will definitely work around high ground bonuses (be if flat or advantage). Say a goblin is hiding behind a low wall, half cover means +2 AC. Getting above enough should negate the cover bonus while keeping realitively safe a ranged character
I mean... Why not ? I'm fine with missing (a lot), but I can understand that some aren't.
then an action rpg may be more suited for those who so vehemently hate missing due to how statistics based rpg works. As a personal experience giving too much flat modifiers to d&d 5e eventually breaks the balance, as this system is NOT designed around abuntand flat increaes to either AC or to hit