I'm surprised to read that using the sleep button and home button combination to take screenshots was only introduced with iOS 2 (iPhone OS 2, actually, in the nomenclature of the era): I seem to remember it presaging that, but maybe I'm mistaken.

Personally I shall not miss the home button, as I abhor it's mechanical nature and have wanted it gone since forever. That said, I'm not very enthused by the iPhone X either, on account of the utter loss of TouchID. I always considered building fingerprint recognition into a screen to be tantamount to science-fiction, but I also kept hoping Apple would find a way of pulling it off well before the feature weaved its way into the rumour mill. Oh well... I suppose it'll be the hallmark feature of iPhone X+1.