Plastic bags are made of polypropylene, and are garbage.

Plastic for the most part is basically garbage, there are so many types that it’s hard to recycle it. PET and HDPE can be recycled fairly easily if they’re sorted, the rest aren’t really worth it (polypropylene, low density polyethylene, PVC).

The only thing that is almost always economically worth recycling is metal, which is separated from the paper/glass/plastic if you have single stream recycling. Plastic should be burned in a cement kiln or buried in a modern landfill, unless it’s well sorted HDPE or PET.