Retail stores.

why would they have any need or business sense to charge less?

Because their business is different from steam? Or maybe because they are more experienced in business and could show the world how it’s done? Wait, why do we even assume that Steam had such huge influence around the time when other digital stores popped up (some of which also didn’t live very long)? The pc gaming was massively considered niche for a very long time, only until recent years. I can’t imagine Apple going “oh right, we are creating our own digital store mostly for mobile devices so we need to check how that PC gaming company does their business, to copy their practices”.

for your original claims

Everything is fine with them.