When you're using Elasticsearch for SearchEngine, there's not many cases where you'll need Zebra to also be enabled (zebrasrv,koha-indexer/rebuild_zebra.pl, filling zebraqueue database table). I understand not everyone agrees with that, so the default should probably be to keep the status quo. But it would be great to have an option that eliminates Zebra from the equation, so that you use less disk space, less RAM, and less CPU.
*** This bug has been marked as a duplicate of bug 21820 ***