Louise Casey's report on the Met found them to be institutionally racist, sexist and homophobic – and in need of radical reform. So no-one is suggesting that there are not problems in the Met (or, indeed, other police forces), or saying that this shouldn't be taken seriously. But "institutionally racist" does not mean that every single person who serves is racist - that applies more to the policies and processes than it does to individual officers (although I accept that there are individual officers who are racist).
It is evident in this case that the vehicle Chris Kaba was driving had a firearms marker on it (with good cause), and that's why it was followed and an attempt to stop it occurred. Nothing to do with the colour of the person driving it, nothing to do with race - everything to do with crime. The police did not act outside the law in this case.
Chris Kaba has a long history of violent crime - he was a gang member who shot people, extorted money from immigrants, and beat up his pregnant girlfriend. I'm really puzzled by how many people are trying to defend him. In your post you say, "Your world sounds a lot nicer, no one does bad things." Can you not see that in this particular case, the bad person who did bad things was Chris Kaba himself?