Yes there is value in being opinionated, but it is less risky to decorrelate the opinion from the foundation. There are opinionated frameworks built on top of react and it is very nice like this. But react itself should not be opinionated.
The team that eventually took it over and grew around it recognized it had some problems scaling and being used for large applications. They knew they couldn’t just change angular 1 to be what it needs to be, so they made a big switch. They put in patterns that benefit large apps, typescript, observables, the choice of two way binding or one way binding, better DI system.
Everyone says react isn’t opinionated, and for developing an enterprise app that just sounds like a nightmare.
ng update is ridiculously easy, and the automatic code rewriting is generally sensible and easy to follow. When there are breaking changes, Angular takes care of the modifications for you. Generally I've felt like those changes resulted in a better expressed codebase (eg RxJS syntax improved massively from 5 to 6, lazy loaded routes are expressed with arrow functions now, etc).
I assumed the React community was also migrating versions with codemods, but maybe React does not introduce any breaking changes?
I mean I hear what you're saying, but Angular is an opinionated framework whereas React is not, and many people end up reinventing the wheel (or an application framework) in the process. There is value in being opinionated.