I have been looking since 2014 for a content management system that is search engine friendly, user friendly and simpler than Joomla or WordPress and I think I have finally found it!
Bludit Open Source Content Management System
The Bludit content management system is a free and open source flat file content management system which is easy to install and use and suitable for simpler websites.
Bludit includes all the basic features you would expect in a content management system such as pages and posts, categories, tags, comments, a WYSIWYG editor, hit counter, navigation, social networking links, search and sitemap.
More advanced features such as contact forms, galleries, popups, basic e-commerce, WordPress importer, RSS feed, embedding a Google Map and embedding a YouTube video are available via the Bludit official plugin repository which currently lists over 100 plugins. Most plugins are free and paid plugins are very affordable.
There are over 50 free themes in the Bludit official theme repository with more free and paid themes available from third parties.
Performance will depend on which theme is used but Bludit websites have low overheads and load very quickly.
The first website I built for a client uses the free "Easy Blog" theme which loads Bootstrap, jQuery, Font Awesome and 2 Google fonts. It still scores an "A" on GTMetrix with 100% on performance and 99% on structure and loads in about half a second (see below). This is out of the box on a budget web hosting plan with no tinkering required!
The disk space footprint for a default install of Bludit is only 7.1 MB which is tiny compared to a default install of Joomla 4.2.5 which uses 87.2 MB or a default install of WordPress 6.1.1 which uses 66.5 MB.
Support is available on the Bludit support forums.