1 World Cup match will be worth 4 Super League matches. The 2018 World Cup raised $5bn in revenue from just 64 matches; the 2018 Champions League had 125 matches and raised a paltry $2.73bn.
This will stay true even if there is 0 star power in the World Cup, because only football fans watch club football whereas humans in general watch the World Cup. My father is a great example. Ask him to name a footballer, he'll say Maradona. Ask him to name another footballer, he can't. Ask him to name teams that play football, he'll say Argentina, Brazil, Germany and Italy. Ask him to name a European club, he can't answer that question.
That's what you're up against. The billions of people like my father whose cash advertisers want, for whom football is something that doesn't exist except for a couple of weeks every four years. For whom European club football is about as relevant as Gödel's Incompleteness Theorem or Wittgenstein's Tractatus Logico-Philosophicus.
Take World Cup participation away from the rebels and pure economics dictates that it will collapse overnight. Where do you think Cronaldo makes his real money, all those stupid Castrol ads or his weekly wages from the thieves? He wouldn't be on any Castrol ads if he couldn't be at the World Cup. It'd be Salomon Kalou or whoever else gets to play at the World Cup who appears in its advertising
Without the opportunity to play at the World Cup, rebel footballers will have the same global reach as professional League of Legends or Fortnite players. Your target market will be reduced to nerds with little disposable income borne from having enough free time to spend 38 weeks a year watching sport on TV, instead of going to a job or better yet spending money on the products being advertised.