I use “intensively” the UK Bomber and I do not feel “lost” when it is downed. I agree with allies_fly, it is an expendable units. Losing even a wing of one Russia fighter is a much grater dramatic situation!
Moreover in many games I bought up to 2 bombers (for a total of three) with UK. In a game after having destroyed the German fleet with them I used the bombers for SBR the Germany, and luckily they were never shot down, but if they were I have not given up, for sure. Usually I do not attack baltic fleet in UK1, if it stay at home, and prefer to add some bomber to the RAF, for attacking in UK3 or UK4. I think that RAF is, complexively, the more inportant force for UK.
I think that other single UK units are more important than the bomber. The BB for example. The Indian AC. (The Indian AAG. :-D)
Nonetheless, I do not commit bomber in battle, like AE counter, were it can only land in dangerous places. One thing is to consider expendable a unit another thing is to leave it exposed to attack, poorly defended and without obtaining nothing in exchange.