There are lots of dedicated cycle lanes in London now which is good. I feel much safer cycling in those.

But as a pedestrian and as a car driver too, there are still a hard-core of dangerous cyclists who refuse to use them and will instead be willfully breaking the law (going through red lights, wrong way/wrong side of the street etc). And just to add insult to injury, they literally add insults! Aggressive shouting, gesticulating etc if your dare to e.g. use a pedestrian crossing or drive on a green light but you are in their way.

Tl;Dr you can build all this stuff but it seems like the aggressive pricks won't use it and will just carry on with no accountability or consequences and we all suffer from it.