It took almost 5 years but the Switch has outsold the Wii, as pointed out by several news sources. The Nintendo Switch now has 103.54 million units shipped compared to the Nintendo Wii 101.63 million.
Nintendo also seems to claim the Switch is the fastest videogame console in selling over 100 million units, but I don't have confirmation of that.
Ironically the Switch shares more that just over 100 million unit sales with the Wii. Both are fragile videogame game consoles with outdated, for their eras, hardware and both have limitations other videogame consoles of their era don't have. For the Wii one of their biggest limitations was that it didn't have enough storage space to have game updates, for the Switch is that the hardware is now so obsolete the only way some games are getting to it is by Cloud gaming despite the Switch being infamous about their online conection issues. They also sold based on being "different". The Wii was different by having a motion controller and the Switch is different for being a portable console you can plug and play on your TV.
The videogame console is also now over five year old and it shows. Many game developers have been asking for Nintendo to release a Switch model with more Ram and more powerful hardware in general and despite the everything shortage Nintendo should really start to do it already.
Is also likely the Switch sales being good is more due to the lack of PS5 and Xbox Series X at affordable prices due to scalping and the shortage.
That being said the Nintendo Switch is still the best portable videogame console on the market with a lot of great games. Just remember that even a basic model PS4 has better hardware and it shows.
Source: https://www.nintendolife.com/news/2022/02/nintendo-of-americas-president-doug-bowser-thanks-fans-for-helping-the-switch-surpass-103-million-sales