Yarn has stated before that the goal of Yarn Workspaces is to provide low-level primitives for tools such as Lerna to use, not to compete with them.

I think the main difference between the two are the way API are served. Some smelte components need you to input big chunk of json as props, while i prefer keep props as primitive types and in the other hand give you different components tags to compose.

On one hand Solid just provides a collection simple primitives like createState, createEffect, createMemo, etc.. These can be composed to create much more powerful behaviors.