I'm kind of the opposite: while I enjoy FaceID and Pencil 2, I have felt from the beginning that the change to the flat back full of magnets design was a step backward for anyone who isn't buying the iPad Pro as a typing productivity device. My main issue is that, without magnets in the spine like the "classic" iPad, cases now have to be folios (or the similar case + cover, sometimes bonded together), and the folios are made even heavier by having to have metal plates in them to work with the magnets in the iPad.
I never felt much need to protect the back of my iPads, so I LOVED the Smart Cover from day one, and still do. It protects the screen and, when folded on itself, gives a thicker, more pleasant grip on one side for holding the iPad while reading. With the iPad Pro, the Smart Folio is quite heavy, leading to an iPad Pro/Air + Folio weighing ~50% more than a 10.2" iPad with Smart Cover, and you can absolutely feel the difference in use. Take the 11" Pro out of the folio and the weight becomes more manageable, but it's no longer that comfortable to hold. I've found that the two part case + covers, while lighter, add a bit too much thickness and enlarge the overall footprint, while never feeling as good in the hand as I'd like.
I'm hoping that the rumored Air-style iPad mini 6 will end up being the best mix of size and features of any iPad for me, as it should be a manageable weight even with a folio case, but I fear that it will feel too small for some of the reading I do (ie, comics or magazine-size PDFs). If that turns out to be the case, I'll be hoping for a future consumer iPad styled like the Air, but with magnets in the spine instead of back to make the Smart Cover still viable.