When an attribute is deleted, it is removed from any related products and attribute sets. System attributes are part of the core functionality of your store and cannot be deleted.
Before deleting an attribute, make sure that it is not currently used by any product in your catalog. An easy way to determine if an attribute is in use is to use the Export tool to check the list of product Entity Attributes. If the attribute is not included in the list, then it is not used by any products in the catalog.
Delete an attribute
On the Admin sidebar, go to Stores > Attributes > Product.
Find the attribute in the list, and open in edit mode.
Click Delete Attribute.
When prompted to confirm, click OK.