Apart from a bit of hard nosed business, you're probably right.
But your rallying cry for 'more sheikhs' a few days ago wouldn't fix anything either. The only Gulf state yet to be represented is Kuwait, that's it. (you could argue Bahrain but they're still on shakey ground with the population so wouldn't risk squandering money on foreign football)
"Why won't Dubai get involved"
Massively in debt to Abu Dhabi, they get plenty of sporting coverage via Emirates sponsorship over all sports, there's no need to spend further. Brand Dubai is doing just fine.
Abu Dhabi (A brother or a cousin of Mansour, perhaps) wouldn't bother, it would be pointless. And if they did, they wouldn't have a serious go.
Saudi Arabia? Newcastle and the PIF is the only game in town. The Saudi Royal family has about 16'000 members, of which about 2'000 have wealth that would make King Charles look destitute.
Qatar? Unless they ditch PSG (which has ultimately failed) they can't really get involved in a big way. As for Shk Jasim, if UTD had a great player that PSG wanted he'd by out the door in a flash. The amount of deference and forelock tugging that goes on has to be seen to be believed. If a more senior royal (this applies to any Gulf state) wanted something, they'd just take it. No arguments.