Earlier quoted context omitted.
I read this sentiment as basically saying the users experience of the app matters less than the experience of the dev who works on it.
The performance "disadvantage" of react (compared to what? SolidJS? handcrafted JS? some WASM thing?) is so small a user won't notice it in most apps in most places even if you don't actually optimize things. Then indeed, abstractions a team can agree on matter more. Getting state management right matters. Hiring people and getting them productive quickly matters. Those are strong points in favor of React and even An…
How can you know this? The only scientific way to approach this question is with real-user metrics and analytics.