Nintendo is not keeping the switch for another 5 years, I am 100% certain they will release a new console before then. They never had a console going for 8 years without a successor. Sales will drop fast, just like 3ds, no way the switch would be selling 13 million in 2025, no way, most people who wanted one already have it, unless they would be sold at 120 dollars in 2025.
You expect the ps4 to sell 6 million until next year? I don't know what drugs are you on, but there will be a price drop, games price drops and a thing called Christmas and blackfriday, the ps4 will sell minimum 10 million until next February, easily. And minimum 5million the year after, because of the low prices, there are a lot of poor people who cant afford 450dollars consoles + 60-70 dollars games. I know of people still using a ps3 and still waiting on the ps4 to reach 150dollars with games.
At current pace the ps4 would sell 7 million, but its a slow month, when last of us 2 releases, the ps4 sales will more than double, and then on black Friday with price drop it will triple. 7 million would be the absolute minimum sales possible, there's less than 10% chance of them selling only 7 million. Maybe if sony released the ps5 at 399dollars which is impossible, as the ssd alone costs more than 100 dollars.
Come back to me when its proven that I'm right yet again.