In fact, about 90% of all hacked CMS sites were WordPress, which is truly the biggest downside of WordPress. 41% of these hacks are due to vulnerability on WordPress’ own hosting platform, while 52% of all vulnerabilities derive from WordPress plugins.
Why? Hackers find that with so many installations that's a greater chance they managed to break into sites. Many Wordpress sites are poorly secured and run as a hobby, so hackers cut their teeth and get success on these before they go for the bigger sites. Breaking into these sites first makes them bolder.
Craft is commercial software, meaning that you get support from Pixel and Tonic, the creators of craft and their concern about security.
Craft makes use of content fields, which streamlines webmasters inputs so they do not have to edit anything else. It is all in text. This reduces the chance of messing something up and keeps the page quick and fast. Wordpress handles complex design with code blocks. Many times using plugins, so the web master has to be careful not touching any block or needing more skills to edit it. This really has to do with a duo creation experience of developers having different access compared to webmasters.
This means the Backend is faster, cleaner and less cluttered with plugins for Craftcms.
The dual creation experience means much better custom designs and widgets compared to Wordpress at less overhead. The drawback of this is that it's more complex for DIY web site authors since you really need a developer for CraftCMS to take advantage of it's power. Since Designers and Developers have their own backend access and the way the content fields are, they can create much more extensive and complex designs while allowing webmasters to edit some of the components in the design.
A drawback is that Craftcms does not come with starter templates since they expect most clients to want more complex designs.
Craft beats many CMS system in performance. The reason is because of its content blocks and non-reliance on plugins. No matter what, if you add more plugins, things get slowed down. In Craft, there is a bit more work up front from a designer side, but you'll reap the returns in the long run as your platform remains more streamline. This turns into performance and page speed. If you want to speed it up on other platforms, there's a lot of modifications and plugins you have to purchase.