I think it's the Chase Trifecta that makes them popular. ie Freedom Flex normally offer 5% cashback on categories rotating every quarter. Cashback is in the form of points but cannot be transfered to airlines/hotels but if you have CSR or CRP, points can be combined nd transfered to partners. Basically you can get 5x points on a lot of categories. It's kinda useless to us as Freedom cards have 3% foreign transaction fee.
I will get Hyatt about 3 months after IHG and will forget about them for a while. With ITIN, I could try do more business cards with Amex. It's normally easier to deal with Chase if you have a longer credit history. If I had to guess, your issue could be the length of history. Hope you get the account back after the review.
My last 2 applications with Chase, they did 2 hard pulls on my credit file sheesh. While some people successfully got them to remove, I was told it was normal.