You can just take the ordinary, classical dynamics of generaelativity and turn the crank on quantizing it where that breaks down. But ok, don't include that stuff. If you want to know why the earth goes around the sun, or why apples fall from trees, you can o you can quantize gravity in this weak field, not very dramatic regime, perfectly well. And that's semi classical gravity. The problem is, no, it is not a step forward toward solving the problems, because all the problems are in the regimes or classical gravity doesn't really apply.