Security
The first point on many people’s minds with WordPress is security. As an open source platform that’s incredibly popular, it can be a target for hackers. This is because with open source comes the danger that anybody can find and exploit a vulnerability in the system. The WordPress team works continuously to firefight this, constantly fixing anything that could become a breach as soon as it’s noticed. These protections are released as updates. Therefore, if you’re not updating your WordPress system with the most recent update, there are known vulnerabilities that you’re not protecting yourself against. This goes for everything from the platform itself to any themes and plugins you have active.
Compatibility
With WordPress, you can do anything. That has pros and cons; unless you’re looking for red flags on your plugins, there’s nothing stopping you installing something that’s out of date and completely incompatible with the version of WordPress you’re running. If you’re not careful, your site can simply break. Look for an up-to-date version of a plugin and install it onto an up-to-date version of WordPress. This way, you’re making sure that your site has the best chance to work the way it should.
New features & bug fixes
Updates aren’t just about security. With each one comes a host of new features and software updates that will improve your WordPress experience. The older your version of WordPress, the less likely it is to offer the benefits that have come with recent updates such as improved image editing, dashboard health checks and accessibility improvements.
Speed & performance
In this day and age, site speed is an incredibly important factor for user experience, search engine rankings and overall site health. With every update comes improvements that can help your site load time. These are often followed by Theme and Plugin updates to match, each improving your site performance.