Residents of every city claim that they have the craziest drivers or toughest streets to navigate in. London isn't really that materially harder to drive in than San Francisco.
But I've lived in both places and London is very different than SF. I'd say the UK has better drivers on average (and much more strict licensing requirements), but driving in London is much more challenging due to the tiny roads you have to navigate. There is no road in SF that is as hard to navigate as the average suburban London two-way traffic single car width road with parking on both sides.
An I'm not saying London is "the worst" by any means. It's nothing like driving in Vietnam or India. But it is very different to SF.
I think you just described the entire Bernal Heights neighborhood in SF (except with 20+ degree steepness on top of that).
It may be true that all major cities have their own quirks, but London has significantly more complexity than San Francisco or any US grid based city with super wide roads.
Also, the US bought into the ‘Car is King’ idea whereas that’s never really been the case in the UK outside of a few places like Birmingham. It’s generally harder to be a driver in the UK.
Whether that causes significant problems for Waymo, who knows? But I am also of the opinion that if it works in London then that’s a pretty powerful tell that they’ve got it right. We’ll, at least for places where drivers generally stick to the rules.