>>713247712They diminished the usefulness of portals by having fewer walls you can put them on and obscuring lines of sight to those walls around the map so it's harder to place them to get good vantages on the go, and they also made the time to kill so fast that any enemy that gets the drop on you will kill you (unless they can't aim for shit) before you even get a chance to respond, so you can't even use portals to escape an ambush anymore.
They made portals an afterthought in the game about portals.