Mr. Fox;
The problem with SBR, is that that Allies can’t effectively use it. Germany has access to 5 or 6 minor and 2 major complexes, so he can simply ignore a significant amount of damage and place nearby instead. If somehow he has to repair, Germany has 60-70$ to do it with. Japan can only realistically be bombed by the US, and then only from Iwo Jima or Mainland Asian bases. The UK only has 1 bomber, and it doesn’t stay up north very often. The US doesn’t have any extra $$ to buy strat bombers with, they are useful but you can’t buy more than a few. Russia cant sensibly afford any, which is why many people give them one to balance things out.
To the allies, it is devastating. “Dark Skies” is an Axis Strat Bomber heavy strategy. With even 6-8 bombers, they can paralyze London, Leningrad, Ukraine, Bombay and eventually Moscow. With more, they can fly anywhere and sbr or strike almost anything. Uk and USSR only have 30+ money and access to a few factories, so they have to repair the damage and they can’t afford to waste even 1 infantry.
Some people have even asked the question why damage the factories that you are about to seize (and then subsequently repair the damage you caused). This highlights the imbalance, the Axis may choose not to bomb in order to capture them intact, using the strat bombers on the attack instead without risking AAA.