You can self level floors because gravity, for walls you’ll need to get busy sanding. A nice excuse to buy an orbital sander. They’re not super expensive and will change your life.
I guess if you layer and layer and layer and layer eventually the edges will soften, but it’s bound to end up looking all heavy and slurryish. Sanding will make it look sharper and moar pro.
You can self level floors because gravity, for walls you’ll need to get busy sanding. A nice excuse to buy an orbital sander. They’re not super expensive and will change your life.