You don't need an account to browse the steam store, you need one to verify you're a user before downloading/installing a game, or (obviously) buying a game.
In a perfect world, you wouldn't need an account to buy or download something, either. It's too bad we've somehow normalized this idea that you need an account just to buy something.
In a perfect world, you wouldn't need an account to buy or download something, either. It's too bad we've somehow normalized this idea that you need an account just to buy something.