Why (from a technical perspective) can't an Apple Pencil (2nd gen) be used with an iPad (7th gen)?

The most obvious difference between an Apple Pencil (1st generation) and a Apple Pencil (2nd generation) is that the latter pairs and charges via the Smart Connector on the side of an iPad, whereas the 1st generation has a removeable cap covering a Lightning connector. The iPad (7th generation) has the same Smart Connector as the iPad Pro, but still can't use the Pencil 2. Presumably there are other hardware limitations that prevent this. What exactly are they? Is there some hardware limitation, or some other reason (other than "Apple doesn't want to support it") why it *can't* be supported?