The norden bombsight was a game changing piece of tech that allowed more precision than had been possible.

The RAF tended to carpet bomb at night, but the USAF wanted to precision bomb by day.

It was nowhere near as precise as today's tech but it vastly improved during the course of the war.

Ultimately it didn't work because the theory didn't work. German manufacturing was not disrupted by precision bombing enough to matter

Masters of the air also touches on this, and some of the disastrous missteps during the raids that led to aircraft loss