Needle in a Haystack
So many craters to choose between, and so many thousands of square km.
It's like searching for a person swept overboard at sea, or for a crashed plane in wooded territory.
With no lives at issue, it isn't worth the effort.
Next time ESA build a lander, maybe they'll put EDL telemetry onto it like NASA had to be reminded to after MPL. That way, at least you know *when* things went wrong and from that can work out *why* they did, and *how* to stop it happening again.