The main selling point here, really, is the things the folding make possible. Spec-wise, it's more in the wheelhouse of the S10 than the S20 (which, as I have mentioned elsewhere, to me feels like a whole load of power searching for a purpose as I don't play high end phone games, and 5G is unlikely to be available in many of the places I need to go in the next two years.)
A phone with a screen I can watch movies on and with that size when closed for stowage? That's an interesting proposition, as long as the hardware holds up.
Also, a customer service bod at Vodafone claims they'll be opening this up for preorder later this month. YMMV.