I play on the hardest difficulty. Again, takedowns freeze the action for the duration of the animation. Go watch a let's play or something, I'm not interested in arguing about it.
Yeah holographic keypads really make traditional ones obsolete, but guess what, slums probably couldn't afford those, or any of those other fancy things they have. Slums consequently look less like slums. There is a lot of technology out right now that makes a lot of stuff obsolete, but the problem is that it's expensive.
Jet based craft for instance burn through fuel very very fast. Until there is some breakthrough in avioic propulsion systems helicopters and other rotor based aircraft are going to be around for some time.
It's like when firearms were first introduced. For awhile, a sword or bow were still more or equally effective weapons. It's not unreasonable to assume that many technologies or at least variants of them will still be in existence 40 years from now.
When we achieve nanotechnological prowess we will effectively be a god race; immortality, physical perfection, endless technological potential, I don't think it's unreasonable to think that it might take half a century to fully realize this technology. That, and the collapse of the global economy as depicted justify the slow scientific progress.