Another userAnother user with full edit privileges made an edit to the postmade an edit to the post after you suggested your edit, but before it was approved.
In such cases, the suggested edit is rejected by the community user and the later edit is applied.
While your edit could have done more, I wouldn't go so far as to say it was bad, just less good than it could have been. Had there been no edit conflict, it's likely it would have been approved.