It's a technical debt trap. You dive in with a one-click install and follow up with a bunch of plugins that seem to fit the bill. Then you spend 2-3x more time creating a custom theme for someone than you would in a sensibly-architected CMS, and only then do you begin to realize that maintenance costs down the road are going to be absolutely crazy. Especially when plugins X and Y start requiring a different theming architecture in production builds, and an immediate update to the latest version is now critical due to a security flaw. Then the plugin you were relying on for sub-task Z is sold to a third party, and while they keep promising to address security and usability issues, somehow you start to receive spam for telecommunications equipment through their support channels.

This actually happened to me. Low-hanging fruit is often a mirage when it comes to the CMS world.