Yes. A WordPress site like yours consist of files and database both of which are required for the normal functioning of the site. Migrating only files may or may not result in normal functioning of the site.      Migrating only files is an added functionality that we provide for cases where the source and destination site are similar in nature(i.e a development and a production site with similar configuration), which is why it is placed in advanced options as this functionality can cause issues when you are trying to migrate sites which are not similar. Though we are here to help you with those scenarios, it is better to know before attempting a migration of this nature.