8Bitdo Gbros. Wireless Adapter for Nintendo Switch (Works with Wired GameCube & Classic Edition Controllers) - Nintendo Switch

https://a.co/d/067qQDwA This is a USB dongle that gives all gamecube and Wiimote peripherals USB and Bluetooth support. 👍

https://a.co/d/08GYmZKG This will give you both GameCube and Wii peripheral support on any device with Bluetooth or USB. They will be widely compatible with most devices now.

I think the Switch 2 controller has some proprietary junk but the Blue Retro developers got it working. Still beta. But folks have reported success. https://github.com/darthcloud/BlueRetro/issues/1249 Another option I use is this: https://www.amazon.com/dp/B07JLF9PVG You can plug an official GC controller into that, then pair that with Blue Retro. Makes a regular controller "wireless". A bit more jankey but it works and rumble works.