Why London of all places?
Deepmind is based there. Anthropic's biggest research base outside the US is there. OpenAI has just announced a big new office there.
It's the place outside US and China with the greatest concentration of AI talent. Deepmind was founded in London for instance.
Sadly UK is fully into nanny state "safetyism" culture so I am not convinced it'd be better.
Talent concentration, little tech regulation, English speaking, decent funding, close to GMT. There's a reason why a big chunk Google deepmind is already there.