I don't know much about the Everton owner but didn't they have to operate on a tight budget because of loss of revenue from COVID?
Newcastle are a big club though, they only need to spend initially to get them to a certain level before it becomes sustainable to justify big sponsorships and whitewash their money through subsidiaries in the Saudi wealth fund. They also have a mad, success hungry fan base, so if they expand the stadium capacity, they can likely get a full house every week, unlike City.
The accountants are also smart enough to amortise any sponsorship deals and player fees over a longer duration of time. They could, for example, buy the naming rights to St. James' park for 50 years upfront.