IMO, one needs to examine the various uses (and difference in muscle recruitment) that DB's can bring, even with the back.
For example, the various muscles that the DB/BB pull-over (and its variants) bring to the table when it comes to the back (such as assisting in developing the: Serratus anterior). Along with the: 45 degree Prone Incline DB-row (which uses two DB's). I have used both of these as SS's in the past.
Personally I prefer heavy BB Bent-Over-Rows, and T-Bar Rows, but I do not self limit my education and examine what other types of exercises have the potential to do (or recruit if you will), and have implemented Wide and Narrow weighted Chins, and the Incline DB Shrug (middle back), for example, as SS's (as well) at certain times in my training.
I remember one time after doing the Bent-Over-Rows and the T-Bar Rows for a few months, I included the Incline DB Shrug into the mix. I became sore in spots that I hadn't before. In this exercise, you get on a Incline (mobile bench), grab "a pair" of DB's, and move both in line with the elbows and squeeze the shoulder blades together in a short motion. My shoulders and upper middle back were sore, which "tended" to tell me something.
Compounds should be the staple (keeping things equal in health and starting point of the person), but one should also examine various lifts (including DB's) and see what it can offer. Some times they have hidden benefits.
Best regards,
Chillen