edit: The reality is they don't spend enough for it to offset the harms that wealth inequality brings.
I know a couple of people who have been using this London loophole as a way to avoid paying taxes anywhere at all. They are not residents here, they are not residents there, and their income is earnt globally. So they think they shouldn't have to pay tax to any particular country.
source? Has "the harms that wealth inequality brings" even been quantified?