in global, SBR has +2 bonus. In the other editions, not. So you do an average of 3.5 damage (5.5 in global) per bomber while taking a $2 risk per attack. Since there is an opportunity cost because the bomber can’t do this and something else, its generally not worth it.
Its more likely that they grab moscow than hawaii, because I typically have a strong us navy in the pac.
and yes, you can kind of stalemate the game by trading karelia back and forth with UK forces, even if you start building up on that side late in the game and have a fairly weak force. But once moscow falls, the money is almost exactly even (85 vs 90) and that’s a loss over time for the allies.