Not to that extent. Currently they’re one generation behind in terms of specs, with the Switch being a bit more powerful than PS3 and 360. Due to the success of the Switch and it’s install base of actual gamers who want to play the new and big games, many devs will put in the extra effort to downgrade their games to get them running on Switch.
In about a little over a year’s time, when the Switch is halfway through it’s lifespan, the PS5 and Scarlett will come out, and Nintendo will be two generations behind in specs. I’m a bit concerned for this period, since it’ll be noticeably harder to take games built for PS5/Scarlett levels of power and downgrade them to PS3/360 levels of power, but I’m hopeful that it will still happen due to the Switch’s install base.
I do think there will be a decline in current big games coming to Switch after next year due to it just being more difficult to downgrade games that much. I think this will be the main factor in Nintendo releasing a Switch 2, with the power of a PS4/XBO, a few years into next gen.
As long as you have lost of owners with money, devs will bring there games down a bit to sell them on the platform. Bringing as many next gen games down two gens may be too expensive and time consuming, or maybe even near impossible for some. They have to move on eventually.