Clients often ask for WordPress because they think they will be updating regularly. The reality is that we spend more time keeping WordPress secure with updates to themes and plugins than the client spends on adding content or new posts. A simple HTML/PHP platform would be much better suited for these low-demand scenarios.

• Less work to customize the template.
• Smaller server footprint, fewer files, No Database.
• More Secure, better control of the source of your libraries.
• Less complicated, Faster loading, Simpler websites,

https://www.slimframework.com/