They only wanted a team that tries...they've got it. They try but generally aren't good enough.
IF they were to be relegated, unlikely but still possible, I wonder if PIF would stump up the cash like Ashley did to get them straight back up? To protect the value of their investment you'd assume they'd have to, but they might also decide to cut their losses and sell up.
How much more dosh are they going to be able to increase turnover by from pulling £750m-1.5bn out to build a new stadium? The ground would take probably another 5yr to build and get fitted out. Even if they already had a site and the necessary planning permission neither of which they do.
It took 8yrs for a brick to be laid at the new Spurs ground from announcing the plans. 3yr to build it. Everton's took 4yrs to start building from time of announcement and another 3yrs to build, but were looking to move from Goodison for at least a decade beforehand.
Two new super stadia, both of which took a decade or so to create. The WC in Saudi will be here before they could realistic start to make this happen and 100% will be more of a priority than a new home for the orcish hordes.