Pick Flutter when
The product is new, you want one UI system, and you do not already have a React Native chapter. Rendering is consistent. Hiring later is fine for most business apps.
Pick React Native or Expo when
Your web app is already React, and sharing types and people matters more than pixel twins. Expo speeds store submits if you stay inside its lanes.
Questions
Will you rewrite later?
Not for fashion. We rewrite if a store or a hardware API forces it, and we price that before we start.