The issue of instakill weapons grows with the TTK for other means of gameplay. If the average TTK is under 10 seconds on usual then an instakill weapon is of no issue. But if the average TTK is 5 minutes, a weapon that deletes you instantly would always bring an issue in balance. This is further enhanced by the fact nanobots exist and that they are completely redundant when facing an instakill. There was a reason people removed full missile loadouts and it was exactly the same TTK issue. And funnily missiles had a downside and risk contrary to the full EMP and SNAC that was the universal standard.
