I'm planning a social media mobile app. I would like to prototype using a cross-platform native solution, leaving room for a future web client. In mobile dev, I'm most experienced with Flutter but I use Next.js for web projects. Since I'm not a designer, I think material 3 would be a fair design system and it's integrated into Flutter. React Native does not have material 3 yet but it would allow an easier web implementation (I have found flutter web to be too slow)

What do you suggest?