A combination of:
1. Extremely easy and friendly immigration policies for world’s top talent - better than in the US
2. Legal ability to easily hire and fire people
3. Legal ability to run a business out of your garage
4. Lower taxes - income, corporate, capital gains - than in the US
5. Free trade, even if unilateral, as the US is involved in tariffs and trade wars
All of this combined, given that the UK is English speaking, could lead to the UK overtaking Silicon Valley in terms of startups. Most of the world’s top talent would, all else being equal, prefer to live around Cambridge than in Palo Alto.