There were android tablets that had them before the switch even launched, they probably have some patent on exactly how they connect, but the concept itself seems too broad to patent.
There were singular units that can also house the phone like the Backbone One, but there were no units that connected physically to the phone via rails like the Nintendo Switch (and this Lenovo device, apparently) does.
Those types of controllers work very differently and thus are not affected by Nintendo’s patent.
There were android tablets that had them before the switch even launched, they probably have some patent on exactly how they connect, but the concept itself seems too broad to patent.
There were singular units that can also house the phone like the Backbone One, but there were no units that connected physically to the phone via rails like the Nintendo Switch (and this Lenovo device, apparently) does.
Those types of controllers work very differently and thus are not affected by Nintendo’s patent.