Bret Devereaux: "it [turns] out that destroying a city [requires] a lot more bombs than anyone had anticipated; the Luftwaffe dropped about 40,000 tons of bombs on London during the Blitz – 133 times the quantity [military strategist Giulio] Douhet thought would compel a country to surrender – and didn’t manage to permanently destroy or even substantially hinder the city. British production rose over the period, albeit more slowly than it might otherwise have."
also, notably, "the Blitz didn’t seem to have meaningfully dampened British morale. Indeed, to the contrary – and get ready to hear this phrase a lot – being bombed hardened civilian will to resist."
"[I]n the aftermath of [WW2], efforts to survey the morale impact of the bombing largely concluded that – wait for it – being bombed hardened civilian will to resist. Together the allies had dropped some 2,500,000 tons of bombs – eight thousand times the quantity Douhet predicted would induce surrender – and the net effect of this was to increase German resolve to resist. "