List some use cases of route groups.

Organizing routes into groups e.g. by site section, intent, or team. Organize routes without affecting the URL path

Enabling nested layouts in the same route segment level: Even though routes inside (marketing) and (shop) share the same URL hierarchy, you can create a different layout for each group by adding a layout.js file inside their folders.

Creating multiple nested layouts in the same segment, including multiple root layouts.

Adding a layout to a subset of routes in a common segment.