While I agree that creating new IP's is an important part of an entertainment company, it's not black and white. Yes, Disney should continue to create new IPs across all of their entertainment divisions, they are leveraging their existing IP's into franchises.
The MCU is an interconnected franchise that relies on existing IP's, whether it be its comic origins, or new twists on existing characters. And some of the newest MCU projects haven't been the best, I don't think interest in the franchise is dying.
Star Wars can continue to exist forever, and it has existed for nearly 50 years. While the sequel trilogy was handled poorly, shows like Mando, Obi-Wan, and Andor have received praise, and is an example of how to do Star Wars right. I think they are using Disney+ to experiment with Star Wars as they plan for a theatrical return. And to argue your same point, I would say shows like Mando & Obi-Wan have reinvigorated the consumer interest that may have been dwindling.
As for creating unique IP's for the parks, IMO, it's futile, and not the best business decision. Synergy is the bedrock of Disney and its parks, and while some may disagree but executing great attractions based on existing IP is a better business decision than creating new ones for the parks. The only way I can see them creating new IP's for the parks is if they were to leverage those new IP's into either films/shows.
I could probably write a thesis paper on IP in the parks and the business logic behind it, but to summarize, and in short: I would say the vast majority of Disney Park guests would prefer IP-infused attractions rather than original ones. Similarly, I would say that Disney prefers IP-infused attractions as 1)it's "more relevant, more timeless, more Disney" and 2) Visiting Galaxy's Edge or riding Frozen Ever After sparks renewed interest in those characters and stories and leads to more merchandise sales, and streaming/Disney+ subscriptions.