I rent about 30 times a year in Asia, but I do not get CC benefits; it shows up in the booking and on the rental contract, but I don't get any of the benefits.

As for renting in the US, I do that about five times a year, usually for a week at a time. So yes it's hard to justify, but in this day and age were every benefit seems to be cut down, it's nice to get really attentive service once in a while.