The real design test is what happens when content changes, products update and somebody opens the mobile menu.
A design has to survive real content
A homepage can look perfect in a static mock-up and fail once users start interacting with it. Long headings wrap differently, product categories change, forms receive errors and plugins insert dynamic elements.
This is especially obvious in WooCommerce work, where the product model and the interface must stay in sync.
Build for the next person
I try to keep content manageable from the WordPress backend rather than hard-coding every change. Reusable sections, readable navigation and predictable mobile behavior help a site remain useful after the initial build.
An attractive interface is valuable. So is making sure an editor can change a service name without calling a developer.
My take
I think maintainability is part of visual quality. Good design should remain good when real people use it and the business grows.