The UK could pitch itself as a place rich US tech companies can buy top talent at low price. I have seen some (not many, to be honest) US tech companies open offices in the UK so they can pay half or less for staff, compared to what they'd pay at home. If Brexit goes as badly as it might, the pound could be even cheaper.
Lot's of companies do that, but the UK is kind of a strange place to choose to do that. If you want cheap, go hire a team of 10,000 engineers in Penang (I'm looking at you Intel). If you want expensive, choose silicon valley. If you want 2nd tier, take a look at Canada. You can choose the UK, but why? Their time zone means you'll never be able to meet with them at the same time as your Malaysian and Californian offic…
Also there is a good overlap for companies based on the east coast to do hand over, which I believe is common in finance.