What process? If you do online check in, you just walk up to the desk, hand them your ID, and they hand you a packet with the room keys. It takes less than a minute. Occasionally they ask you if you'd like an upgraded room. For "check out", you either do it in the app, or just leave.

Now, if you don't check in online, have special requests, or want a paper copy of your bill, those are all processes. But the mobile key doesn't help with those.

That said, other than shaving a few seconds off the check in process, I don't find online check in that helpful either. As others have said, if you could select your room like in the Hilton app, it would make a lot more sense.