5. You CAN Wall Run
Unlike Titanfall 2 where you can sprint across vertical surfaces at insane speed, this overarching "method of thinking" has been taken away in Apex Legends, replaced with grounded, boots-on-the-ground altercations instead.
Clearly this is done to get across the aforementioned "combat legibility" the team were striving for; and to not have encounters where players could mess with each other too much in terms of pulling off acrobatics or manoeuvres that feel unfair.
However, wall running is in the game - but you can only do it in a straight, vertical motion.
Jump towards any surface and keep holding forward to climb up. The game engine is very good at identifying which surface edges you can mantle onto thereafter, and as your vertical sprint comes to a close, you'll end with an automatic jump that will nearly always see you make the gap regardless.
Use this to get great vantage points on top of roofs or to tuck away inside the dinosaur bones of Skull Town - other squads will not know what hit them.