From my point of view if you stay at US properties most if the times by far, then just do your math about the point systems, check, which guaranteed benefits gives YOU more value and find out, which credit card offers you the desired status without being forced to spent most/all of your stays at the same group. Just check that 3 points. It doesn’t matter, at which brand you get inferior service by untrained underpaid staff in their 2nd or 3rd job.

I‘ve had top tier status at some loyalty programs in my life and all of them were less worth in the US. The US is a country for high priced hotel stays with inferior service. Even in the best times of IC Royal Ambassador - there best status at that time from my point of view - my experiences at US properties were below average. You can see many guests from the US crying out of happiness when they stay in Europe or better Asia and getting a great service or even a great breakfast.

The only good point about hotels and the US is, that as an US citizen you can get a high status by credit card easier and for more brands than in most of the other countries.

From my point of view Hilton offers the higher rebate by its point system, good properties to redeem outside the US and the top tier status is easier to get by credit card.