30% - Switch Only
31% - Switch and PS4 Only
23% - Switch and Xbox One Only
17% - Switch and PS4 and Xbox One

According to NPD's Mat Piscatella:

A healthy primary console. The switch 2 should follow suit if it's an evolution of the switch.

Wow, Switch owners so starved they need other consoles to be full.

It was sarcasm. I play Nintendo games 90% of the time. 

This seems to me a pretty strong indication that Switch coexists rather than directly competes against PS4/Xbone.

Interesting numbers. This also means that atleast 47% of PS4 and atleast 40% of Xbox One owners have a 2nd or third console.

Interesting data regarding console users. I think this shows that even with a power gap and being a little late compared to PS4/Xbone, the Switch can more than handle its own as a primary console. Even though there are very few current-gen AAA titles and very little of the big annual titles (i.e., Madden, COD, new features on FIFA beyond the basic ones, etc.) on Switch, it appears to have a compelling library that seems to satisfy a decent amount of people to warrant being a primary console, at least in the US if we were to go by the NPD report. So even if the PS5/Xbox Series X (and Lockhart) come out, I think the Switch will be fine as it has features the latter two do not have and those features are enough to entice current and new consumers to the console.

We need PC percentage as well, how many Switch owner has PC, ( I am just saying before someone else said)

Where does it say which is the primary console?

If you shuffle (randomise) a pack of playing cards, how many cards would you have to turn over before you could accurately predict that they're 50:50 red/black and 25:25:25:25 hearts, diamonds, spades and clubs?

If you shuffled a billion packs of playing cards, how many cards do you think you'd have to turn over before getting a 95%+ or 99%+ accurate result?

(a random sample of 1000 is enough to predict a population size in the tens or hundreds of millions)