Not remotely true. There are plenty of web apps that work just fine with a standard fixed set of API endpoints with minimal if any customization of responses. Not to mention the web apps that don't have any client-side logic at all...
GraphQL solves a problem that doesn't exist for most people, and creates a ton of new problems in its place.
The value of GraphQL is also its downfall. The flexibility it offers to the client greatly complicates the backend, and makes it next to impossible to protect against DoS attacks effectively, or even to understand app performanmce. Every major implementation of GraphQL I've seen has pretty serious flaws deriving from this complexity, to the point that GraphQL APIs are more buggy than simpler fixed APIs.
With most web apps having their front-end and back-end developed in concert, there's simply no need for this flexibility. Just have the backend provide the APIs that the front-end actually needs. If those needs change, also change the backend. When that kind of change is too hard or expensive to do, it's an organisational failing, not a technical one.
Sure, some use-cases might warrant the flexibility that GraphQL uses. A book tracking app does not.