@Cheese9Man It's rarely proper to call similar features "copying". For example, I have created a circular menu that is very similar to the ping system years before Apex, but it wasn't working for that particular project so it got dropped. I'm pretty sure there were other games with similar things before Apex,Respawn didn't invent the (ping) wheel.
Also, you need to consider the fact that devs do switch studios often and they take their experience and style with them. Respawn had devs coming from / moving to Blizzard, Epic, Infinity Ward, etc., it's not unusual. If you see in Apex skins that look like in Overwatch, behind those there might actually be a designer that has worked at Blizzard.
Anyway, it matters more whether a new feature works in a game, rather than it being original or a copy. Not sure if wall running would work that well in Fortnite, but adding such a feature would actually be a good thing for Respawn, as they would get credited for being the main inspiration.
Another thing: not all studios are at competition. Most of them respect each other and would happily collaborate from time to time. I think the future will bring more collaborations, in the style of Destiny x Fortnite at least.