The screenshots on the website are taken with every setting maxxed, potentially using some of the bells and whistles which are in the settings mainly for filming purposes like lens glare. All that requires a lot of computing power which is why disabling or reducing them is often recommended for a playable frame rate.
Another thing to consider about the web page screenshot is that they've been chosen from thousands of screenshots. It's like photography: The light is just right, comes from the right angle, there's no disturbing objects in the background... That can happen every day. But once in a lifetime something special appears into that perfect stage, bathing in the light like a goddess unaware of you watching and if you're lucky the lens cap isn't on, the focus is spot on, no cloud sails across to dim the light, no seagull splurts on your lens, no bumble bee flies past just as you snap... Professional photographers can name their best single shots from the hundreds or thousands they've published, and to every published one there's hundreds that haven't been worth publishing. The best AH screenshots are similar, often taken from a filmed session where you can change the viewing angle to catch the fanciest glare.
