I think the topic of LibAdwaita was discussed plenty when shit hit the fan 2-3 years ago. Downstream developers can’t act all innocent and misinformed now when there was a huge drama between Budgie and GNOME upon LibAdwaita’s announcement.

GNOME developers repeatedly asked downstream developers to stop theming their apps which was generating endless bug reports for issues not caused by upstream code and none of them bothered to listen to them or work with them on a fix. Their choice of developing their own widget kit is a wise one because they’d otherwise still be wasting valuable developer time on fixing issues they should not be responsible for.

When one doesn’t take “no” for an answer, you’d have to forcibly make them stop. Just my two cents 🤷🏻‍♂️

If you're THE leading DE project at least try to accommodate those DE's that depend on your code or meet with them to inform them well in advance and discuss the best options for those DE's.

It's always easy to say that other people should do more work to benefit others. Libawaita isn't anything new. It was announced loads of times.

In other words, work together for the good of all users

That the current status isn't what you want isn't the same as not working together. Further, there's usually a limited amount of time and attention.

Within Linux there's loads and loads of opinions. Loads of different desktop environments. That complexity cost development time. Time that isn't infinite. Again, it seems to easy to direct how others should spend their time and/or to argue that they aren't doing enough for your liking.