I think this somewhat inevitable given the flexibility of javascript. The lack of convergence on one single paradigm as a long-lasting set of best practices speaks to all of things that a web framework needs to have in order to accommodate all developers.

In Svelte's case, it feels like they went as far as they could without directly addressing observables until they reached a point where it became one of the largest features that had yet to be addressed.

Open source frameworks, not unlike companies, need to continue attracting new users to grow the ecosystem, which means pleasing an ever-growing user base.