Flutter Web WASM is set to be out later in 2023 (Google IO?) [1] and should fix the performance issues.
I have build big Flutter Web Apps and Performance was the only real issue, hope it is improved soon. Things like not selectable Text like the Author mentions just show that he does not really know what he is talking about. Just use the SelectableText Widget that is exactly the same as the Text Widget just that is is well, selectable.
I absolutely think the team will largely fix the performance issues. And I think Flutter will, after that, go on to be a successful-with-developers but terrible-for-everyone else beast.
The submission early on links the wonderful "HTML is the Web" and this is a huge downgrade in user agency. Flutter does not care one iota that "The Internet is for End Users". [1] They have their own goal to build native like apps & are fine subverting the web. User agency be damned.
I have heard that WASM and potentially some engine upgrades could aid the performance but I think it's still too early to say they'll be a definite fix, I'm looking forward to testing it out though once it lands.
Hopefully it helps out on lower end mobile browsers too as that's where Flutter Web really tends to chug.
I have build big Flutter Web Apps and Performance was the only real issue, hope it is improved soon. Things like not selectable Text like the Author mentions just show that he does not really know what he is talking about. Just use the SelectableText Widget that is exactly the same as the Text Widget just that is is well, selectable.
[1] https://docs.flutter.dev/platform-integration/web/wasm