Nobody wants to wait for their code to get in.
You can either use the branch protection in your repository or write finer-grained conditions in your Mergify configuration. Define which checks are mandatory, the number of reviews required, etc, to get a pull request mergeable.
Mergify updates the pull request status in real-time and informs you about which criteria match. As soon as your condition is validated, Mergify merges the pull request using the method you specified.