If one has a gold card or better from the credit card company, that includes
insurance for the collision damage waiver portion of rental company insurance.

For USA cardholders and rentals in USA, perhaps. There's a whole bunch
of people for whom neither applies.

That rather surprised me. I have similar Mastercard credit cards from
HSBC in the US and the UK. The US card includes rental car cover,
like all high-end US cards do, the UK card doesn't.

R's,
John