Environmental and NPC excitement...
I'm a huge fan of the game, which should be obvious from my play time. I'm not sure if this is in the works, I've heard rumors, but I think these two aspects would push Apex Legends to the very top of Battle Royale if these are implemented correctly.
*Add environmental hazards to the map with high risk and high reward mechanics. Such as valley with lava that is a high tier loot, but not platforming correctly could cause you to fall into the lava for instant death. Or, using the Swamps as an example, have Toxic Gas plants littered around the area and if you step on it's vine or get within certain proximity it can cause a Caustic-like effect which players could strategically shoot to escape someone or blind someone.
*Add NPC mobs to the game such as Crocodile type mobs in the swamp, to ravenous Sabertooth Tiger in the desert that hunts the kill leader (or opposite, hunts lowest (weakest) kill/damage player in the area), to Yellow Jacket nests that hang off trees and buildings that can be shot which causes a DOT (damage over time) area of effect. Stuff like this would make all the running around the map more exciting and add so much more fun to the game.
These were just some of my thoughts that would keep me interested in the game long term and would push Apex to the top.