https://www.thehindu.com/sport/football/fifa-reserves-at-4-billion-after-world-cup-more-to-come-in-2026/article66511381.ece
For any country that host the world cup they will have many benefits and that's not just financial benefits they will get, sometimes the fan who comes to other countries for watching the world cup games will use the restaurants and they will buy food or they can use the hotel which can have many benefits and it can even provide more demand for their business.
Yes, it's a win-win for all who took part of the FIFA World Cup even if they are directly or indirectly part of the event as the viewers, players, even the organizers will certainly order good food from the restaurants, food stalls and kiosk near them. And then there's the hotel/AparTelles which will accommodate all the people who will watch and participate the long event.
Regarding with the forecasted revenue in the 2026-2029 cycle, that is really achievable knowing that 3 countries will host the said event and a lot of people will flock towards the country as this time, a free country will host the games.