Dart 3 apps new class modifiers (dart-lang/language#2242), and the core libraries have been updated to many cases to use these. For example, the platform class in dart:io is now abstract final.

In the current DartDocs it's very hard to see these modifiers (e.g. platform). They are shown just textually near the top:

I'd like to suggest the following improvements to make class modifiers more clear:

1. Show capability chips after the class name (similar to the chips we show on API members in the rest of the page):

2. On generative constructors, show them as now available (e.g. using strikethrough text) with capability chips detailing why. From @lrhn the combinations where the constructor isn't available are: a) sealed, b) abstract final, and c) abstract interface).