Great questions, and of course the answer is “it depends”

There are some options:

Use your existing Nuxt app and components, and just wrap the app in Capacitor to build for mobile. For this, you would want to ensure your app looks and feels like a mobile app for user experience on each platform, since you aren’t using Ionic components.

A hybrid approach, where you integrate Ionic components in your Nuxt app when building for mobile for components that don’t have a native look and feel already. Then using Capacitor to build for native.

Using Nuxt with Ionic and Capacitor and doing a larger overhaul of using all Ionic components for mobile for the highest out-of-the-box native experience.

It will depend on how your existing Nuxt web components will look on mobile, how important a native mobile experience is to your users, and how quickly your team can integrate Ionic components into the exiting web app codebase.

As for performance, it again depends. Nuxt for web provides some great performance features because of Universal/SSR rendering and hydration, however that does get lost on mobile due to the issues I mentioned in the first response. Because of this, you may want to measure things like bundle size, initial load time, etc. when using Nuxt vs Vue for mobile. I haven’t done any measuring but there may be some stats out there, although Nuxt for mobile is still pretty new so you may want to do a POC and test it.