We've all seen the 'billionaires get bored and move onto the next plaything pretty quickly' argument when Roman bought Chelsea, the again when City got bought out. Let's be real, it's just about prestige, like horse racing or formula 1 teams. They will not be doing this short term, that would be an embarrassing defeat on the international stage, they simply won't allow that to happen.
History is full of embarrassing defeats and arrogant men overestimating their clout.