Are modules required for this scenario?

I am building a ReactJS app with a Yii2 RESTful backend. There will be a frontend and a backend (admin) section. The 2 sections will be by domain/subdomain i.e. www.website.com/api (frontend) admin.website.com/api with .htaccess routing to either index-public.php or index-admin.php, with each index file having it’s own config (obviously) for it’s own models and controllers as well as common models and controllers.

In a scenario such as this - given that there will be nothing other than a RESTful service provided by the backend (i.e. no views/layouts) - is there any real benefit to having base\Application extending from base\Module rather than just directly from di\ServiceLocator? I want to reduce the required code/files down as far as I can and I cannot see any scenario where I will require a module\parent module - all functionality (including bespoke functionality) will be in the form of components.

Thoughts?