But I doubt that was due to phones. It's more factors like set top boxes, "smart" TV's with built in streaming apps and casting, and the decline of the need for DVD/blu-ray players.

I remember the days of the PS3 where many bought it simply because it was the cheapest Blu-ray player (which is saying something, given its slow adoption rate and infamous "599 USD" reputation), but consoles as a multimedia device has definitely fallen off. It's also infamously one of the worst market reads in the industry when Xbox One decided in 2013 to advertise as a set top box on its reveal over a gaming console.

But unlike handhelds, that lost "non-gaming" market did get made up for with a growing market of dedicated gamers (indicated by games continuing to sell increasing numbers of copies). So it simply evened out instead of trending downwards.