It'll take a generation to change and until they fundamentally overhaul their recruitment and vetting methods they haven't even started.
When I joined I was interviewed, interviewed at home, my old CO was interviewed, friends were interviewed, they dug into my backstory and references to a squeaky degree. This was done by an inspector and a PC, both coppers, both experienced investigators and interrogators. No copper with a nickname 'the Rapist' would have been able to transfer into the Met under that old regime.
Now its in the hands of HR who do no such thing, who rely on paper references, who make no enquiries as to the real integrity and suitability of the candidate. Until that initial point of contact for candidates is kicked into touch then nothing from that point onwards is likely to change meaningfully.