yeah. That's all what bagged soil is, peat, perlite and sometimes coco. With very little nutes. Dr. Earth is mostly peat and uncomposted compost. Imo super soil is over rated. There's better mixes.
my mix is cootz recipe.adjusted
peat moss, pumice or perlite, coco, worm castings, compost. kelp meal, crab meal, neem meal, glacial rock dust, volcanic rock dust, basalt rock dust and oyster shell flour.
I use homemade vermicompost (worm castings n compost mixed)