Ernest, the main developer of Kbin, has given an explanation of what has happened: https://kbin.social/m/kbinMeta/t/544021/So-what-s-the-status-on-the-update-edit-ernest-responded#entry-comment-3006120

Kbin is about 3 months old whereas Lemmy is about 3 years old. Kbin simply wasn’t ready for growth, and still has a few major feature shortfalls. Lack of API access is a big one.

You’d think this would be one of the first things they get working…