There are exceptions. I believe the Kia Telluride SUV is sold as AWD and it has a locking differential system (or at least it’s an option). There are probably others as well.
A proper locking differential found in most traditional 4x4 vehicles/trucks, when engaged, physically locks the axles together which means they cannot spin at different rates. This is essential for many more rigorous off-road applications when you may have to rely on traction from a single wheel to get you unstuck.
This is exactly the type of misleading marketing that is described in many other comments. A clutch pack cannot physically lock axles together in the same way as a locking diff.