From my experience working in finance in London, no.

Good salary? Sure! Able to live comfortably with 50% salary (when rent is 30-50% of take-home pay)? Zero chance.

In practice the biggest impediment to even longer non-competes is legal risk; the tiny chance of an employee challenging the non-compete in court and the court ruling unreasonable or overly broad, would result in all other employees knowing their non-competes are effectively void.