According to Glantz, the Soviet use of long range bombing units in a tactical and operational role was because of the severe losses incurred in the early stages of the war. As the DBAK formations were mostly in STAVKA reserve, they suffered less during the initial stages of Barbarossa, and thus were thrown into battle in a tactical role. The result was that they were annihilated, and by December 1941 only 135 bombers remained. The loss of experienced crews meant that by the time the front stabilized and STAVKA began reforming DBAK into the ADD there were few trained crews remaining. Despite this, by early-mid 1943 the ADD was larger than it was pre-war! But due to poor crew training and the lack of good bases it was again used operationally and tactically.
So it seems that, if the VVS isn't destroyed pre-war, and if the Red Army is able to retain the use of the Crimea or various Baltic bases, the DBAK will be in a position where STAVKA could use it in a concerted strategic campaign, rather than piecemeal raids of less than 100 bombers. There were a number of German/Axis allied industrial areas, rail centers, oilfields, etc which were out of range of Allied bombers until much later in the war.
While I agree that Soviet efforts would be very costly and unlikely to produce immediate results, OTL that shows they had the resources to invest into long range bomber forces. But it seems that with increased experience and development, several hundred more aircraft and crews than IOTL ready for raids, and useable bases, a strategic bombing campaign could do quite a bit of damage. Not decisive in and itself, but certainly more than a wasted effort.