The vendors can use the Magento 2 Manage Attribute feature to delete the attribute those are no more required.

To delete the attribute

1. Go to the Vendor Panel.
2. On the left navigation bar, click the Product Attributes menu.
   The menu appears as shown in the following figure:
   
3. Click Manage Attribute.
   The Vendor Product Attribute page appears as shown in the following figure:
   
   All the created vendor product attributes are listed on the page.
4. Scroll down to the required attribute to delete.
5. Click the respective row.
   The editing page of the specific attribute appears as shown in the following figure:
   
6. Click the Delete Attriute button.
   The product attribute is deleted.