Evolution of technology makes things unstable, not specifically servers. A decentralized application is not more stable than a centralized one. It depends on what's prioritized about the product. For example, you can still use SMTP servers developed several decades ago to send email to others.

Also, it is hard to buy the argument that docs based on Google Docs will live less longer than docs served by some CRDT-based collaborative application. It is easy to argue the opposite. My Google doc history shows docs I have even forgotten ever existed, and Google docs play nice with Microsoft Word - making it interoperable with the largest ecosystem around structured documents. Again, this is about product features and prioritization, not underlying building blocks.

CRDTs hold a very special place in my heart. But I also believe they don't offer a differentiated solution - on the user facing side.