What about not-so-smaller apps?
I also maintain a large app in SolidJS. I like SolidJS even more than Svelte, especially for large projects but also for small projects.
Svelte has some disadvantages with tooling & some issues with Typescript integration. SolidJS allows more function decomposition & general flexibility in creating smaller more focused components, since the jsx/tsx components are plain old javascript functions. In addition, SolidJS javascript output is smaller than Svelte when the app hits a fairly low level of complexity. The engineering of SolidJS is more accessible than Svelte, so it's easier to understand what is going on.