This is not the usage of the word "settlement" which prevails in the financial industry, which tends to use it to describe the transfer of funds to give effect to a promised transaction. It is factually not the case that credit card payments generally settle instantly. It depends on many factors but typical timelines are a few days to about a month, largely dependent on which network is at play and where the business getting paid is. (For complex reasons, prevailing settlement times in some countries are long compared to most HNers expectations.)