FIFA survives because it effectively sanctions competitions at every level. Take Manchester United: they play in the English Premier League. That competition is sanctioned by the English FA - a member of UEFA, the European body of FIFA. If United make it into European competition, they play in a competition organized by UEFA. Their players represent their national teams all over the world, and compete in matches run by UEFA, CONMEBOL, and other FIFA governing bodies.

When Manchester United announced they were joining the Super League in lieu of the UEFA sanctioned European competitions, the FA announced that they were at risk of expulsion from the English league structure because the FA bylaws say you can only play matches sanctioned by FIFA/UEFA - essentially pulling the league and cup competitions away from them and turning them into a glorified exhibition team. And the fans went ballistic at this, for good reason.

Was the ESL a trial balloon? Almost certainly, and we will see something similar, possibly to just force UEFAs hand in negotiating things like revenue sharing. But supplanting FIFA would be much harder than “throwing money at the problem”.

10B probably isn't even enough to buy out the PL, much less the world football pyramid.