If you currently own the iPhone 11 Pro Max or iPhone XS Max or you're planning to buy one in the near future, the iPad Mini 5 won't have that much appeal.
The iPad mini 5 uses same 7.9-inch screen size as previous models. This isn't surprising because if it went any bigger and it would likely cannibalize 9-inch iPad sales. Any smaller and it's creeping into iPhone XS Max/iPhone 11 Pro Max territory.
We've been using the iPhone 11 Pro Max and iPhone XS Max since their respective launches and we don't see any reason why we'd want to pair them with an iPad Mini.
Their 6.5-inch screens are perfect for playing games and doing work on the go, two of the primary uses of a portable tablet like the Mini line.
They also sport excellent battery life making it perfect for a short trip in the car or long distance air travel while in Airplane Mode.