My biggest issue is… many of the plug-ins that are out there simply fail when installing on my latest installations.
And it is not like I tried. My first site install was under Ubuntu 24.04LTS and using Docker… and after the initial install, almost every rebuild after adding in a few plug-ins (which showed to be recent and supported -yeah, right) the rebuild of the Discourse app took a dump all over itself and failed regularly.
Then when I would try to rebuild with those plug-ins removed… back to failing.
My ultimate solution was actually moving back to a AlmaLinux install with Docker. At least now when I add a plug-in that the current version does not like, I can actually rebuild the app when I remove it from app.yml., unlike on the Ubuntu install.
And no, I am not a new admin to running websites. I’ve been running forum based websites for over a decade, having experience with Woltlab, Xenforo, Invision, SMF. phpBB, myBB, NodeBB and several others. and even going back to the era of MS-DOS/DesqView and multi-node BBS’s (ultimately an OS/2 Maximus/2 multi node system with 4 nodes and 3 of which were direct access by users and all 4 of which were available to process FidoNet mail). So I am not new to the scene.
I like what I have seen of Discourse so far on my site I am running it on. But I can quickly see where people new to running a self-hosted site may have issues with it. I currently also run Xenforo and NodeBB on several sites… and honestly, the NodeBB setup for a multi-site system is MUCH easier to deal with than the Discourse offering. We won’t even get into where running 4 nodes of NodeBB on the VPS instance has less impact than a singular Discourse Node on a VPS install And yes, I have investigated the use of multi-site on it… but it’s really more hassle than it’s worth currently. And yes, I do like to play with various scripts.. and I have no issues with pointing out warts that I find with any of them. 
Discourse has a solid base.. but it still needs to make it easier for admins to run multiple sites when self hosting without having to jump through the hoops it does currently.