I'm helping overhaul our church Website. The old site was built in Joomla 1.5, and the new site is in Joomla 3.6 (I didn't choose the tech). Joomla's supposed to be a pretty popular system so I'm amazed at how much I dislike it and wondering whether there are better options available. There are a lot of small annoyances, some major design issues, and some really bad bugs.
One fundamental issue is that it's very difficult to work backwards from viewing a page on the site to being able to change the content on that page, until you've studied Joomla and the site internals to figure out how the pages are assembled. I had to read a lot of not-particularly-well-organised documentation to grasp the concepts of menus, articles, components, modules and templates, then do hours of spelunking with Firefox devtools, browsing the administrator interface and making educated guesses to figure out which page parts were generated by which Joomla entities. It seems to me that this could be a lot easier, either by offering WYSIWYG tools that show you visually how a page is assembled (and let you edit those parts in-place!), or at least by leaving consistent notes in the generated DOM to indicate where pieces came from. Simplifying the assembly model would also help a lot.
Another fundamental issue is that there's no version control or change preview. As far as I know the only way to figure out what impact a change is going to have is to make it on the live site. It might be possible to set up a staging server, but that looks difficult, and probably impractical for a small-ish project like ours. If you don't like the effects of the change you have to reverse it manually, which is horrible and error-prone. Without version control there's no way to view changes made by others, make experimental branches, etc. The two latter problems would not be improved by a staging server.
Those issues seem so fundamental to me I'm surprised a major CMS fails on them.
Then there are the bugs. My least favourite bug right now is that often, when I edit HTML using the WYSIWYG HTML editor, upon saving the article the targets of all links are replaced with the target of the last link (destroying my work in a non-undoable way, see above). I assume such a terrible bug must be specific to our installation somehow, but the system is complex and opaque enough that debugging it seems impractical.
Our church's needs are not complicated. The site is mostly static and there isn't a huge amount of content. Nevertheless the pages load quite slowly and the generated HTML/CSS/JS is bloated. It's tempting to start over with a completely different approach. Then again, I know there's a plethora of CMSes and Web frameworks and Joomla is very popular (at least in absolute terms) so I feel like there must be something I'm missing.