I imagine that spending is dominated by a few major categories, which you can find specific cards to cover. There are spending limits, but you can always get mu

I imagine that spending is dominated by a few major categories, which you can find specific cards to cover. There are spending limits, but you can always get multiple cards. I do that with BoA, I have 2 basically identical credit cards, but each has a different bonus category set, or I can set both to use the same category like dining out. So unless you're spending like 200k net a year on life expenses, it's pretty easy to get the max returns.