If you value build size you might want to take another look at Svelte. Build size is one of its strengths. For example, the Svelte implementation of RealWorld is roughly 10% of the size of the React/MobX implementation:

https://medium.freecodecamp.org/a-realworld-comparison-of-fr...

Edit: Confused the React/Redux implementation with the React/MobX implementation the first time around.