These “bombs” likely fall dozens of miles through the air travelling at about a thousand feet per second. They absolutely have a guidance system to keep them on course, basically exactly the same as a missile except without the rocket.

The only real difference between a missile and a “gravity bomb” is they have to be closer to the target when they are “fired”. Oh, and gravity bombs are cheaper. A lot cheaper.

Even if you never fire a missile they still have to be maintained. See Russia vs Ukraine war… It’s estimated 60% of Russian missiles don’t even explode at all. And the ones that do are often nowhere near the target due to a guidance system failures. If they were properly maintained they’d work better than that.