It's not just lost keys. Drop a mechanical key in a puddle, no big deal. Electronic key?
Fortunately a replacement key for my car costs about $2. That's fine with me. (In a blizzard a couple of years ago, I dropped my keys in a snowbank, only to find them after the snow melted. They still worked fine)
I carry my own electronics rather than have it installed in the car.
-- FORTRAN manual for Xerox Computers --