Other sites like Photos are fast and performant, but I wonder if it's due to whatever perceived advantages of Wiz or due to the team actually caring: https://medium.com/google-design/google-photos-45b714dfbed1
Edit: replaced incorrect link with a correct one
Wiz is designed to make it harder to get bad metrics if performance is not your top goal.
Even though it's claimed that it powers many of Google's websites, most of those websites are very far from being paragons of performance.
As an Angular developer you could expect new features and developer experience improvements. Also over time you’d see more of Angular used in popular consumer Google products.
It sounds no different from Svelte borrowing concepts from SolidJS, or Vue borrowing ideas from Svelte, from you said — if it is just adding some features that Wiz has, it doesn't sound like merging? Why put a shocking title that Angular is merging with Wiz, when Wiz has no name recognition in the outer dev community — like we don't know what that means?
We're working on making RxJS optional. In v17.3 `@angular/core` no longer has a dependency on RxJS. In the long-term we'll enable a path forward without RxJS for other core modules as well.
That said, we're providing an interop package that enables even better RxJS support for people who make the decision to use it.