it’s the way the map design is…if you’re say pushing down numbani A mid, with tracer, soldier, zarya, rein, zen and mercy, you’re going to have a hard time because there’s nothing to contest the high ground with if they say have a widow, junk,etc.
even if you engage from the high ground you gotta drop eventually, still with nothing to contest the high ground.
there’s a lot of high ground in this game and more often than not it’s not easily accessible for the attackers.