I think this is the argument that the Ladybird people have made:
- Chrome is dependent on Google ( obviously )
- Edge is dependent on Google ( based on Chromium )
- Firefox is dependent on Google ( 80% of revenue )
- Safari is dependent on Google ( $4 billion from Google )
- most other browsers are dependent on Google ( use Chromium ) - Brave, Vivaldi, Opera, etc
Ladybird is intended to be a truly independent browser and especially independent of Google.
They have been migrating to GTK3 since before GTK4 was out.
I am sure they will stay behind but future porting should be easier.
That said, non-GNOME GTK apps seem to be considering sticking with GTK3 anyway ( to avoid libadwaita ).
https://linuxmint-developer-guide.readthedocs.io/en/latest/xapps.html