I'm no JS fan but this argument doesn't make sense to me - just pick from the big ones at random then? Far more weight behind them than Flutter, and I don't know why they get the higher bar of being 'evaluated' between when Flutter doesn't because it's the only option and you're stuck with it.

But anyway if you want to use Dart & Flutter fine just use it? My comment wasn't about why someone shouldn't, it's why I think people don't, i.e. why it doesn't have that much adoption.