The web is definitely incapable of hacking the speed of light, though. And if you want truly instantaneous search - I mean deterministic, keystroke by keystroke - you have to put your data as close to the customer as possible, ideally right on the same device, ideally right in the same process.
Is this necessary for most commercial projects? Of course not. But many of the programs I consider the nicest to work with today are that way precisely because someone fought back against the call of the network.