1/ why’s it ‘attempted’? I was robbed, the fact they then discarded it is secondary. Good luck for me, apart from the minor damage but still theft.
2/ If they had a number of reports last night in different locations maybe they can work out a route and maybe from that trace on CCTV. Or maybe they caught them later in a sting and can add others to it. Not often that less information is useful.
3/ Because if everyone that got lucky ignores it you don’t get a true picture of the issue.
You still possess the phone, it wasn’t stolen, they attempted to steal it.
The fuzz may use your report for ‘intelligence’ so it was worth reporting.
The Met have been ‘stats driven’ for too long and to the point of idiocy. I doubt they’ll even class your report as a crime because it’ll go down as ‘unsolved’.
Still a shitty thing to happen either way.