Not as many easy paths anymore for a British worker, tech or otherwise, thanks to The Foolishness.
And the most popular choice -- the USA -- is off the table for the majority of Brits, I think, who cannot comprehend The Other Foolishness. (Mind you, the ones it encourages... I hope they follow their hearts)
That is straightforward to the point that a British citizen can just go there and work, even go there and freelance.
(I have given it some consideration myself.)
Generally speaking, though, it's not a route Brits take in huge numbers, for legacy reasons. Though plenty investigated their potential for citizenship.
And the most popular choice -- the USA -- is off the table for the majority of Brits, I think, who cannot comprehend The Other Foolishness. (Mind you, the ones it encourages... I hope they follow their hearts)