This particular press baron doesn't necessarily seem to have spent his entire life (nor, arguably, have kept all of his fortune) in England / the UK, either -- among the bits I didn't include in the above quote(s) is the information that, after having concluded his public school education, he literally vanished from sight for decades, only to resurface transformed into Lord Comstock, millionaire press baron. Though of course, if he'd spent time anywhere in the Commonwealth (I suppose where exactly he vanished is part of the things we're bound to find out in the course of the novel), part of his earnings would still have ended up in the UK treasury. And the way his press "stunts" are described, there's no question that he would have lionized social media like Twitter -- they'd have played right into his hands.