I can see it now....'XYZ bank' forms a consortium, buys the LOT, then changes the airspace to ALL Controlled, REQUIRING Full Flight Notification, and .....wait for it......Charging accordingly.
Not necessarily so, Griffo.
Quite a few international ANSPs are not for profit organisations that are typically owned by the relevant government (usually 49% ownership but with a golden share) with the remaining shareholding being held by a combination of commercial air carriers and general aviation organisations, unions and even employees.
International ANSPs that come to mind that fit this model include NATS (UK) and Nav Canada.