[toast0]

> Old-school" key ignitions work perfectly fine, so why were they replaced with the obviously-flawed dongle?

It's more convenient to leave your keys in your pocket or your bag, then to rummage around for them.

There's a terminology problem here. I don't believe this is a replay attack (same open command is replayed later and works), those are largely solved with rolling codes. This is most likely a relay attack, the distance from the car to the key is bridged with a repeater. That's harder to solve --- you could measure distance by round trip time, rather than by limiting tx power, but the distances in question are small, and the timing difference between keys at car door and keys at house door isn't very much. Probably the crypto takes longer and may vary more than the difference in transmission time.