Explanation:

The asset relationships object is used to track when equipment has been swapped out by creating parent-child relationships between assets. Adding the related asset related list to the asset page allows viewing and creating asset relationships from an asset record. Adding the field history tracking related list to the asset page would track field changes on an asset, but not asset relationships. Adding the product request related list to the asset page would allow requesting products from inventory for an asset, but not tracking asset relationships.

References:

https://help.salesforce.com/s/articleView?id=sf.fs_asset_relationships_overview.htm&type= 5
https://help.salesforce.com/s/articleView?id=sf.fs_asset_relationships_create.htm&type=5
https://help.salesforce.com/s/articleView?id=sf.tracking_field_history.htm&type=5
https://help.salesforce.com/s/articleView?id=sf.fs_product_requests.htm&type=5