The last time I was running a cluster it was 2014-2015 and it was not too bad to get up and running, but it felt so heavy handed for what it was. The zookeeper requirement was frustrating. The fact that consumers needed to maintain offset state was frustrating (although... understandable). For the right use case I suppose it is 100% worthwhile but more often than not I have seen it used in places where other tools would be more appropriate.
They've made Zookeeper optional now, although they're being understandably conservative about that (e.g. only declared it production-ready a year or two ago).
