Which of the two has better prospects career and earning wise?

Banking and Finance any day. Plus, I personally know folks moved out to Singapore and Dubai.

I know 2 senior folks from banking who moved to London then came back. People underestimate the cultural difference, one’s own ability to make friends, live without a support system. Lot more than just doing a job.

IP Litigation lawyer will make much more if you're successful and established. That'll take 10+ years and tremendous luck for the money to start rolling in. B&F in a T1 firm will give you a comfortable life within 10 years when the struggles of the litigation lawyer have not ended