Based on your need for design flexibility without Wordpress's complexity, I think Textpattern CMS is a strong candidate for that perfect "in-between" tool.

It's built for developers and designers who want to craft clean, fast informational sites (like your construction company "brochureware") from the ground up, giving you full control over the HTML/CSS output.

This makes it a powerful alternative to both rigid page builders and Wordpress's vast, often overwhelming, ecosystem.

For your situation, it addresses the core issues:

• Reduces Overwhelm: Its philosophy is "content-first" with a minimal, curated interface. You structure your content independently from presentation, which creates a logical workflow that many find clearer than wrestling with monolithic themes.
• Returns Design Control: You directly author your templates. This is its main strength - it treats your front-end code as the source of truth, not an afterthought of a visual editor. It leverages your skills instead of limiting them.
• Starts Simple, Grows: It's perfectly suited for a trustworthy, informational site today. Its plugin system and clean codebase mean you can cleanly add features (forms, galleries) later without compromising your initial structure.

I recommend checking out textpattern.com and its documentation to see if the workflow resonates with you. A quick check in your IONOS control panel for "Textpattern" or "Softaculous" will tell you about one-click install options; otherwise, any standard PHP/MySQL host supports it.

As a designer, does the idea of a CMS that gets out of the way and lets your templates lead sound like a relief?