I can certainly imagine the UK doing well in some tech niches, but not in high-end, global scale consumer electronics like Apple, no.

The high-end mobile phone market outside Apple is a shark-infested red ocean to start with. Then there's the fact that even if Apple stopped operating in the UK, you'd still have to compete with them globally.

I cannot foresee a Black Swan event like a random dude from the Midlands becoming the next Steve Jobs, but other than that I don't think it's worth entertaining that there will be a real British contender to the American trillion dollar mastodon.