I've been working with three flutter apps for the past two years (Android and ios), and the improvements in the platform performance have been consistently trending up.
One of our apps has 6 video players running at one point, and that doesn't seem to tank performance, there is an integrated Unity game and several other 'heavy' features. It's resliant and performant for the basic task of getting content on the screen. Then dropping down to the individual OS for certain features (video etc) is a breeze.
My only gripe is it's not opinionated enough as framework, and tries to be all things to all devs which makes Architectural changes contentious against competing opinions. (See trying to implement a the latest Router from scratch)
The downside is the mess of flutter web.
As an engineering team everyone can be Flutter dev, but only a few have to be a Kotlin/Swift dev to implement features.
nb: RN, or Flutter are still more competitive than Maui however.
nb: RN, or Flutter are still more competitive than Maui however.