What apps etc genuinely benefit from a big square screen?
3D Game engines seem too, Office, email and browsing apps etc will work fine on it too, as will opening of multiple viewports of such things, I do this already on my Note 10+ but the screen isn't really big enough to be super useful beyond 2 apps.
Also most of the camera sensors aren't actually 16:9, that is just an option, so full pixel shots will hold up well.
There are generally a lot of benefits to a bigger screen but do agree this is by no means perfect, really it needs to be thinner in the hinge area and some how magically open up to around 10 inches, plus be water proof and support the pen.
Perhaps a future Fold Z will come out with an actual Z fold for big tablet madness (maybe why they choose Z name in the first place) but you need to go through the early stages before you can get to that point.