It's not even outselling the PS4 on a weekly basis. It had a strong first year, but Nintendo came out guns blazing with new Zelda/Mario Kart/3D mario/Splatoon/Xenoblade 2.
It's gonna be difficult to top that in the following years.
Also, people seem to forget, but the gen is gonna move in 2 or 3 years again and Nintendo will be left generations behind in tech once more.