In terms of the amount of people who own phones and PC's vs consoles; absolutely correct.

This is the CEO of Sony talking to investors who are looking at the big picture, he's not posting on a gaming forum.  There were like 1.5 BILLION smartphones sold last year.  Physical consoles are a small market that will probably get comparatively smaller over time.

I'm not sure why people would argue over the nuances of the word "niche," either--isn't this a translation from Japanese?  

We can talk about the translation but until someone gives us a different translation it's what we have, he was referencing console gaming when he called it niche when the facts don't back that up. it's plain that this is Sony positioning themselves to be a part of the technological future that includes streaming and AI ,and I can't see anyone with any sense of foresight not agreeing with this venture, obviously he was trying to demonstrate that the deal was bigger than just the gaming side ,What he should have said is this venture and the growth we expect to emerge from it cut's across many divisions besides Gaming like Imaging, Movies and TV  to name a few and confining the discourse to just the gaming division misses that point. Instead of doing that and just playing up the deals scope he had enough insecurity to feel that he had to sell it at the expense of publicly questioning his companies policies concerning subscription models.

Technically, he's totally right, as every kind of activity is it's own niche of activity. That niche might be huge (see the Marvel Cinematic Universe for movies, for instance), but it's still a niche. Anything that isn't technically niche doesn't have it's own niche and is doomed to fail. Even a monopoly would technically be a niche - it just fills it up to 100%.

Console gaming is a huge niche worth many billions, so it's rare to be called a niche, but it's one nonetheless, just as is PC gaming, tabletop gaming or mobile gaming.

Niche is a specialist segment of the mainstream the important words for you to think about when deciding if you considering something niche are segment and specialist.

Gaming has been niche for decades we just see it as big because it's our hobby and the industry generates a lot of money for its size, 120m or so gamers out of 7 billion people the industry is mainly carried by a handful of countries in 3 regions so he's not wrong.

The thing is he didn't compare it to the worlds population and anyway it's silly to use our 7 billion population since just about everything is marginal when that's your comparison point, plus niche is a specialist segment of a mainstream enterprise and where did you pull that 120m from?.

Its niche because sales outside exclusive boxes are much bigger than 200m consoles sold.

Kinda surprising when PS4 really helped Sony in a tough earnings time. I laugh at the notion of game streaming on anything other than a mobile device. When almost all entertainment is streaming and you live with others, even streaming on a local network is trash from device to device. But whatever, I have a nice backlog to last years and if that is my only option is to stream then to the localized backlog will be fallback and fuck the industry.

Compared to television, electronics manufacturing and some other industries it's niche.

All consoles combined get about 200M sales on 7B population.