Yeah, you might be right with both titles. I can totally see people getting both games, they probably end up being really solid for people who are into those. But is it enough? For me, I can answer that with a strong "No.". But I guess we will see what the general public thinks.
For me, I see Miles Morals more as a cash grab, not really as a full blown sequel but I love to be wrong on this. But I am not a big comic book guy anyway... And with Demon's Souls, this will sell for sure. From what I have seen, BluePoint aren't really getting the atmosphere right, IMHO. Feels different than the original Demon's Souls. They also changed the art direction to a more "comicy"/generic gothic style. And the gameplay footage lacked that "tactile" visual feedback. Combat looked a bit disjointed. But again, that's probably just me.
How is it a cash grab? They didn't have to do anything, but they started another game right after 2018 spiderman, and also sometime in 2019 started development of a new ratchet.(or at leas thats when rumors hit, could have started much earlier)
They are literally making two games? One is smaller in scale and seems to serve as a big chapter to go into a much bigger story arc with possibilities leaning towards a spiderverse type of game series with different characters.
It may seem like a cash grab because it's smaller, but I think making a stand alone miles story was always in the cards. If you didn't get that from playing spiderman then you never played it, or dont know how to pay attention.
Playstation makes money for Sony, like a lot. And they know their game division is their biggest money maker. SO they invest in tons of projects, exclusive deals, VR to serve that whole division to make the most money they can.
How can you not look at the last 2 years of playstation and see their investment? 2018 God of war, spiderman, 2019 days gone and timed exclusives from third party, 2020 had Last of us part 2, Ghost, FF7:R.
Microsoft's last two big games were Ori will of the whisps, and Gears 5. gears tactics did all but dick and was only available for PC soon to be console.
Next year is stacked with first party and third party exclusive content. And 2022 looks like it's going to be a banger as well if rumors are true.