Both can quickly change a site’s look (using Themes) and extend its functionality (using Plugins) available from a wide range of third party developers worldwide but they have a different architecture, history, and target market which makes direct comparison difficult past a point. Both are powerful and highly extendable but October overall is cleaner, clutter free and friendlier to use in our opinion.
At October’s core lies an elegant, clean Laravel PHP framework with lots of potentials, and no blog. Out of the box, it has a minimal modern dashboard with the ability to make clean, semantic pages, and that’s all. It doesn’t force resources upon you that you may never need but it does help you to quickly build, scale, and develop just about anything you do, including blogs.
You can find a more detailed comparison between the two at https://www.smashingmagazine.com/2019/03/wordpress-october-cms/.