The Project Browser aims to simplify the process of finding and installing modules for both site builders and developers. You've got two options: First, you can use the browser to search for modules and see the necessary Composer and Drush commands for installation. Second, you can actually install modules directly using the UI.
Right now, the module is in beta, and the feature for installing via the UI is still experimental. I gave it a try and encountered some errors, so it seems we'll need to wait a bit longer for it to be fully reliable. That said, the Project Browser is already a handy tool for browsing modules. It's more user-friendly than drupal.org, thanks to improved search and filtering options.
This Project Browser is part of a larger effort to make Drupal more accessible, especially for those who are new to the platform.