If this includes improvements to the screen recognition feature in Voice Over, it could provide accessibility for apps where the developer doesn't care about accessibility, which is extremely common.
The vision capabilities could be useful if they are done well, but I suspect that will always be covered better by 3rd party apps.
Additionally I don't believe this is just marketing. This is adaption to a changing market. Apple's customer base is aging and having these kinds of features will allow them to keep using Apple products for a longer.