This is exactly what people don't understand is happening. My son is training to be an actuary with one of the UK's largest finance/insurance firms. He and his cohort are nearly all planning to leave the UK once qualified. He is regularly attending leaving "do's" for other qualified actuaries working there who are emigrating. He says it's like a mass exodus - very few of them are actually planning to remain in the UK. He never even thought about emigrating when he first got the job, but it's the main hot topic conversation in the workplace.
Not only there. One of his Uni flat mates who is a trainee accountant with a top 4 accountancy practice says she is also planning on emigrating once qualified and apparently the sentiment is rife throughout her firm too among the young graduate trainees.
I have my own small accountancy practice, I don't have too many clients, less than 100, but over the past few years, 15-20 of them have emigrated, being a mix of freelance accountants, freelance IT contractors, freelance actuaries, etc - all very high paid.
These kind of professions are now highly mobile and they can literally work from anywhere in the World with a decent internet connection. The tendency is for them to relocate and work abroad, but many of them are still "working" for their previous "employers" based in the UK, but instead of the UK getting their income tax, NIC, VAT on spending, etc., other countries such as Canada, New Zealand and Dubai are benefitting instead.
People need to wake up and smell the coffee and start understanding what the World looks like these days, and stop the stupid glib comments of "don't let the door hit you on the way out" - it's childish and illinformed.
Look at Lewis Hamilton - not only "living" outside the UK to avoid UK taxes, he also bought his private jet via the Isle of Man to avoid paying UK taxes on it. Go back a few decades and NIgel Mansell moved to Isle of Man to avoid paying UK taxes as the IOM is a well known tax haven. Even Tyson Fury is rumoured to be "moving" to the IOM to avoid punitive UK taxes on his multi million pound income and assets.
We NEED the richer people, the higher earners to stay in the UK, spend in the UK, employ in the UK, etc. The last thing we need is for more of them to disappear abroad and pay their taxes to other countries, especially when their incomes are derived from the UK!