Suitability for Complex Applications

Hello All, I am working on a freelance project and I want to know which one is good to work in complex applications between flutter and react native. Yesterday I search on google and according to this post, Flutter isn’t yet capable of developing complex applications. As applications with extensive features and functionality require extensive customization, this cross-platform application development framework doesn’t emerge as a suitable choice but not an idea about react native. Can anyone know? which one is good between them?