Most of Kadokawa's business comes from mangas and light novels. It doesn't make sense for Sony to buy them. They are cheap but the only worthy asset is the game business.
Anime and Mobile gaming. Kadokawa is an extremely close partner with Sony, and yes, in the big business of Anime creation (especially with the increase in the streaming market) and Mobile game (especially gacha games) they have a big market in common.
Forget Fromsoftware (which is just icing on the cake), Sony buying Kadokawa, or at least securing a strong partnership, makes a lot of sense in many markets for both companies.
Prediction: In 5 years Nintendo will Lauch a "Core Mario game" very similar to Astro Bot. That said, many will Ignore Astro Bot existence and say Nintendo created this concept.