This blog will help you to create your own customer attributes in Magento 2 programmatically which allow adding more specific properties.First of all, you should have your own Magento 2 Extension. See how to create your module here.
Step 1: Create InstallData.php file
Step 2: Modify data input for each kind of attribute
Step 3: [Optional] Customize layout
Coming back to this many years later, it just occurred to me that the is_active flag is probably present in any [EAV]_entity table because, at one time before the earliest releases, all entities were in a single entity table. When EAV entities were broken out into their own tables, this column went with them.
Best guess! ¯\_(ツ)_/¯
Check below code
InstallData.php:- sets up data when the module is installed.