The design and doctrine placed around the SVD rifle in the very late 50's and on was to augment a Soviet squad with longer range capabilities than their standard AKs. Essentially to supply precision fire out to the longer than AK ranges.
While they wanted this particular role to emphasize that DMR function, they didn't want to lose that 1 extra soldier in the squad should the need arise for other combat needs.
The PSO-1 scope was quick detachable, not only to protect the glass, but also to allow the SVD equipped soldier to join his squad in CQB while using the rifle's iron sights.
As technology progressed these rifles can (and are) augmented with more dedicated CQB optics for that CQB role. Obviously this is not a rifle you'd pick for CQB if you had the choice, but what happens if you have to press it into that role?
In this video we use the 2G-ACM match as a laboratory to put that idea to the test!