Yea the lanes thing is definitely more apparent on escort maps but controlling flanks exists on every map so that's just how I think of it. The no damage fall off is really great for early poking before the real fight starts just to do some free damage, maybe drain some resources, and build your ult charge, but consider point 1 defense where you posted up on the high ground behind the main archway. By the time the enemy team has gotten to that archway choke Mei's poke value has already gone down compared to her brawl value. Instead if you started behind that blue car and poked down that long lane as they walked up to the choke and then backed up to brawl as they attempted to cross the choke 1) her primary fire slows them so they'll spend more time in the choke, 2) it does cleave damage to multiple enemies at once, and 3) you'll have quick access to that door on the left to control that flank. In general controlling high ground is good but only if your team has someone with an effective range utilizing it, or denying it from an enemy team that wants to use it. In a perfect world you and bastion would have swapped places here and he would utilize the high ground while you controlled the left flank.