Taking the footnote out of context makes it look sillier than it is. Here is the actual quote where the footnote was used:
> This makes the new iPad up to 5x faster than the best-selling Android tablet, and for users looking to upgrade from a device like iPad (7th generation), they will see up to 3x improvement in overall performance with the new iPad.
The footnote also mentions this immediately after your quote ends, which you presumably left out because it would have made the theme of the above quote more obvious and less confusing:
> Best-selling systems are based on publicly available sales data over the last 12 months.
If Apple clearly states they are comparing to "the best-selling Android tablet", and they do, then I don't see what the problem is. They didn't say "compared to the fastest Android tablet" and then whip out the old MT8768 or some nonsense like that. The reader is welcome to disregard the comparison, but the comparison isn't misleading.
The basic iPad has surely been Apple's best selling iPad for a long time, so that is Apple's point of comparison for this one. If they wanted to compare absolute performance against the best the Android tablet market has to offer, they would use the iPad Pro with the M2 chip, not the basic iPad.
I would also point out that anecdotally, I don't know a single person with an Android tablet that cost $200 or more. I know plenty of people with Android tablets that cost way less than $200. Most people reading Apple's comparison who have an Android tablet will be trying to understand why they should pay the premium for an iPad instead of buying another $100 tablet, and being 5x faster is a logical hook. People with a $400+ Android tablet are unlikely to be considering a basic iPad, since they've clearly already made up their mind.