You are correct to an extent, and 100% correct when looked at as a whole. However, I will get more granular to explain what I mean.
In order to keep a level playing field years ago the governing bodies implemented a salary cap, otherwise you would get the situation where those teams with the most financial clout could in theory offer players ridiculous contracts and see players wind out their contracts with the relevant franchise they are with - which is seen a lot in football these days a la Sanchez. One method to create that level field in football is to adopt a alary cap model. The issue is there is not the appetite for it from the clubs, especially the rich clubs who stand to lose the most out of anyone, and because of that UEFA and FIFA can not exact any meaningful change, which is why the teams at very top very rarely leave. NFL owners have tried and failed in the past to get salary caps amended or scrapped to ni avail because however much they are despised the NFL are more powerful than the club owners, especially when it is only the minority that want change
However none of that will be replicated in football so no chance of not seeing the very rich constantly winning the relevant leagues