-
Are you suggesting that having a financial industries is totally worthless to GDP?
This suggests they pay £10's billions in tax.
https://researchbriefings.parliament.uk/ResearchBriefing/Summary/SN06193Whether they should pay more ("yes") is probably a discussion one should have quite apart from the one where we decide to just give up on the industry.
-
It's an open question whether they're a net gain or a loss. Some argue that the overall effect has been negative, short-termist, destabilising and predatory.
In short, financial services of the kind where there is very little trickle down of wealth. And not much tax paid.