Currently all javascript modules are loaded when a user enters an item's page. However, most of the javascript modules are only used for editing, so they should be loaded when actually clicking on edit and not from the beginning.
For example, when clicking on [edit] in the sitelinks section, then and only then the modules for editing sitelinks should be loaded. Same for all other modules like entitytermsview and statementsview. This will improve performance a lot and decrease the time it takes for users to load a Wikidata page.