I don’t own a car and rent whenever I need one. The car rental insurance with my card has been fine in my experience with the one exception being Salt Lake City. About a year ago I was there and they wouldn’t let me take a car unless I gave them a car insurance policy number to put into their computer. Despite being completely fine in the entire rest of the world, apparently Utah does not accept “I will use the insurance provided by my credit card” as a valid explanation… I was forced to buy the rental company’s crappy insurance that would have likely done more harm than good by buying it.