And to add to that, the creative possibilities of cross-IP pollination between Sony IP and, say, Square-Enix or Capcom IP. Not even just limited to gaming. Stuff like Captain Commando x G.Police (or Colony Wars), or a spiritual successor to Omega Boost with Cyberbots/Tech Romancer characters (such a shame Polyphony never returned to the Omega Boost IP). That's on top of bringing back IP like Parasite Eve, ActRaiser, Onimusha, etc. The merchandising, film, anime/manga etc. potential, and more.
For me it's not even about getting rid of Xbox: I don't necessarily want Xbox to go away, though I wouldn't lose any sleep if it were to happen, either. Over time it's been less of a net positive on industry growth and creative innovations than say from 2001-2008, and I simply dislike the militant toxic culture they've grown and cultivated online. I wouldn't feel like the industry loses much in terms of gaming tech innovation or cool, innovative software the way it did when Sega stopped being a platform holder, for example.
But in terms of Sony securing PlayStation's future, you're right, they have to be looking long-term and just getting more 3P exclusivity deals, or doing 3P exclusives with unproven teams for games that are several years out and no IP power of their own, or thinking over-relying on PC ports and live-service/GaaS military FPS sci-fi shooters won't secure that great of a future for the brand. I don't jump up at the sales milestones or the fiscal quarterly results or stuff like that; I can acknowledge they're great milestones to hit but they don't speak to the long-term health of the brand, either.
People have to stop thinking Microsoft are some completely incompetent company; you don't need top-tier competence when you have more money than common sense, and can just lock out your competitors of most of the big content over time. Where they can't provide a genuine option for customers, who are then forced by default to pick your product instead. That's ultimately what Microsoft wants; that's a death siren for the larger health of the industry and potentially even hobby.