Stable release: Improvements for Construct Game Services, desktop exports, 9-patch, performance, and lots more.
You and most others. The new exporters are simply incomplete and don't fix a single thing they were supposed to improve upon over NW.js.
We were struggling to keep track so we made this toadlobe.github.io/c3-export-compatibility you might be interested. As you can see still a lot missing
They are getting there
That's the thing. They're getting there - they're not there yet.
Why remove working tools in favour of broken ones and force users on to them?
They're removing a feature that's becoming hard and time-consuming to mantain, in order to speed up the development of other features (and "get there" faster). I don't think they're forcing users, the 449 LTS will still receive critical updates and is supported till the end of 2026, and I assume for that date, the new exporters will have fully catched up.