Its web targeted version is still not accessible, even though they promised that they will actually render to HTML elements as much as possible. A single canvas element is not that.
https://medium.com/flutter/accessibility-in-flutter-on-the-w...
> The Flutter team would like to eventually turn the semantics on by default in Flutter Web. However, at the moment, this would lead to noticeable performance costs in a significant number of cases, and requires some optimization before the default can be changed
But good. That's a kind of progress.