To be honest (and partial, since I haven't self-hosted many contenders), I didn't find Matrix that complicated to setup. The most complex and resource-hungry part is federation, but you can likely do without if you don't need it (since it is one of the biggest selling points of the tech, I am afraid there shouldn't be many guides omitting that part).
I did it trough Yunohost on my server, but I hear there is a handy Docker-ansible playbook, and that the Archlinux package works pretty well (synapse is also available trough pip).
I guess someone could cook up a non-federating server implementation some day…
The trend of commercial open source apps to be a major PITA to deploy & hack on is kind of tiresome imo.