If your site requires no updates, regular changes, or any additional content, HTML is a better choice as it will make your website perform faster. If you want to grow your business website and constantly update it, then WordPress is the best choice.
WordPress websites have an underlying content management system software which makes this type of website flexible and easy to customize. On the other hand, HTML sites don't have any underlying software — it's all code which can be great if you're a developer, but difficult to manage if you're not.