They should just explain how advantage works and add less cheated way to get it ?
In D&D even help allow you to get an advantage. The optionnal flanking rules, hiding/surprising, shove to prone. Bless is also a powerfull spell that increase your %to hit and lots of us suggested other bonuses to attack roll for highground (and/or backstab even if it's an exploit of the TB system).
Okay it's easier to have an advantage but players that complain about missing doesn't play with them and/or they don't understand at all how to create a character. This is because the games lack of tutorial and nothing more.
I still don't understand why they implement faery fire at all and why hiding is possible in combats because its 100% useless (except to bug the AI). The spells that grant advantages/disadvantages are nearly never used by those ending the EA in solo and that's because except in very specific situations : it's a waste of ressources.
More flavour (to quote you) and a game that is not more difficult for newcomers ? Just increase the max party size ! Even 5 would be enough !
And/or allow us to stack a few new bonuses to attack rolls if missing is a problem instead of destroying a core mechanic of D&D to create a cheap core mechanic in your game (kangaroo TB exploit / highground god mode)