Being the smallest, this is more pertinent on the EDZ map than any of the others, and it goes like this: the invasion alert goes off and in the time it takes for the brain to process and react to that information I or one of my team is already dead because the invasion spawn point for the Ruins is one jump away from having a sightline for a good chunk of the map and most importantly, the Bank. Something something Sleeper, something something Malfeasance, something something wallhack. The delay wouldn't have to be much longer than two or three seconds, and that's all the time the defending team would need because the only thing more infuriating than dying instantly to an invader is dying to an invader you aren't even aware is present.