Other tools have very slow performance. They are usually selected because someone on the team likes Angular, but your customers won't care what framework you're using. They'll just know the app is slow.
Fluentd offers true log streaming rather than log batch processing. Its technically possible for logs to get lost with logstash and we didn't like that idea. Fluentd offers a better cloudnative experience with the expectation of failure whereas logstash is better for infrastructures that don't have the expectation of failure.