A building I'm occasionally responsible for locking after the hirers have left has a number pad on the main entrance, with separate numbers issued to separate hirers (I'm not sure how this is managed) but also various locks using conventional keys (which the hirers don't have to bother about). I've no idea how the number-issuing works (I'm not involved in that) but obviously it helps track who's been in and out when, as well as reducing the number of physical keys to be lost or copied (legitimately or otherwise). Such a system might also be useful in family homes but doesn't seem to have generally caught on.
I think possibly car keys are what strikes me as odd though. They all seem to be electronic nowadays, certainly for the doors and often for the engine too, yet you still have a – rather large and heavy – physical object to carry around. Is that bit really needed nowadays, isn't it just a hangover from the old tech? (Bear in mind I haven't owned a car since 2007, so am probably wildly out of touch here.)
Which reminds me that on Saturday, walking through a small village (North Stoke nr Bath if anyone wants to know), I stopped to look at the village notice board. These can be great fun. In this one there was a large photo (on actual photo paper) of a tree with some sort of metal disc in it. I noticed the board was only fastened with a simple turning latch (no key, no lock!) so I opened it to have a look at the photo (which turned out to have a semi-literate conspiracy theory-style diatribe written on the back: "They're killing the trees and no one gives a shit.") As I opened it, out fell a car key which had been wedged behind the glass. VW. There were no VWs in the vicinity so evidently whoever it belonged to had got their car home without it.