> How does that work for any other industry in the UK?

I don't know about other industries but in silicon there are a few hubs - especially Cambridge, Bristol and London.

When I lived in London there was a big start-up scene around Hoxton.

It's not going to happen for consumer product type things (think Dyson) though because none of the manufacturing is in the UK. Who gets injection moulding done in the UK? Nobody. Dyson is a rare exception and even then it's only R&D that happens in the UK - manufacturing is all in Malaysia.