I’ve just started learning Svelte for a side project, but I think you can make an argument for developer productivity with it too. React doesn’t have a monopoly on that.
What if you don't need a massive ecosystem? For example, the project I am currently working on has (checks package.json) react-router, react bindings for redux, and react-spring (the latter could easily be dropped; it is almost not used). Plus Storybook, but that's not even react-specific. That's all.
The ecosystem is more than the libraries. Do you use the VS Code or WebStorm integrations? Do you use one of the many options we have for bundlers and dev servers? Do you use the browser dev tools?
Svelte has to recreate plugins for all of these things and more. I haven't yet tried Svelte (I'm waiting for Svelte 5), but the tooling needs to be at least comparable to Vue's if I'm going to consider adopting it.
It doesn't need wrappers to the same extent React, Angular, et al do. Svelte works quite well with vanilla JS libraries without having to implement a wrapper most of the time.
