Commercial yeast is a single strain bred for speed. Sourdough starter is a wild culture of dozens of yeasts and lactic-acid bacteria. That difference explains almost everything else.
Flavor: sourdough wins on complexity — tang, nuttiness, and depth from long fermentation. Yeast bread wins on neutrality when you want the bread to disappear behind the sandwich.
Digestibility: the long ferment in sourdough breaks down gluten and phytic acid, which is why many people who feel heavy after supermarket bread do fine with a real sourdough loaf.
Shelf life: sourdough's acidity holds staling and mold at bay for days longer than a yeast loaf of the same size.
Effort: yeast bread is a three-hour project. Sourdough is a two-day one. If your kitchen life is busy, commercial yeast is a legitimate answer.