The 8bitdo adapters are a work of art. You can use them to connect a PS4, PS5, Xbox controller (and I think their compatibility is not limited to just these controllers) to Windows platforms, Nintendo, Steam Deck, and mobile devices. I'm not sure if they work for PS4, PS5, or Xbox consoles, as I have never tried connecting controllers to such consoles using these adapters, but it is certain that they support the connectivity of PS4, PS5, and Xbox controllers with Windows devices, Nintendo, Steam Deck, and mobiles. I just want to emphasize something important! The 8bitdo adapters need updates at specific intervals through the 8bitdo firmware updater application that you can install on your computer from the official 8bitdo support website. If the device ever stops responding to a device like the Nintendo Switch (which was my case), you may need to update the adapter through this application. The process is simple. First, you install and open the 8bitdo firmware updater application. Then you place the adapter in a USB port on the computer (while holding down the pairing button as you place it in the port, otherwise it won't show you the list of devices you want to update). Next, you search the list that appears for your adapter, and once you find it, you select it and install the latest update. There are several devices in the list that look like your adapter, but in reality, they are not your adapter. If you select the wrong device in the list, it simply gives you an error message that the device you chose to update is not the correct one. So you scroll through the list until you find the right one.

I have had it for several months. It works perfectly. I have only connected it to a PS4 Controller, but I never had any disconnections or difficulties in pairing them. I didn't notice any delay in response.
The only thing you need to remember is that you cannot "wake up" the console from the PS4 controller, nor can you exit a game. No matter which button I pressed, it didn't wake up or take me to the Switch's home screen to change games.

Edit: On 23/4/2022, I decided to upgrade its firmware from version 1.32 of 2020 to the latest one, I think it was 2.02. Since I did that, I regretted it. As soon as it connected to my controller on the Nintendo Oled, it would lose connection with the PS4 controller after 2 minutes. I tried a second controller, same issue. In communication with the company (prompt response to my emails), what they suggested didn't fix it. In the end, I reverted back to the version I had and everything was fine.
P.S. The adapter and the controller worked without any issues on my computer while I was playing, it was only on my Nintendo that I had the problem.

Excellent connection with the PS4 controller, it recognizes it properly from the Switch and PC, I didn't feel any difference between the joy-cons or the PS4 controller, so there was no delay in connection or input delay from the controller.

The connection to the Switch with the PS4 controller was simple, you plug the Adapter into one of the USB ports on the Nintendo Switch dock, open the settings, and enable the PRO SWITCH WIRED CONTROLLER SETTING.

Press a button on the USB Adapter located below the indicator light that turns on.

After pressing it, the rate at which the indicator light on the USB Adapter flashes changes to indicate that it is ready to pair with another controller.

Depending on the controller you have, press the corresponding buttons on it. For the PS4 controller, it is Select + Playstation button (the middle one with the Playstation symbol), and then it connects on its own.

After doing this, go to the controller menu in the Nintendo Switch's settings and press R1 + L1, and it's ready.

I didn't encounter any problems with the product, nor did I need to do any updates. It is cheap and practical because it works on the computer as well, and now I don't need to have extra USB cables on my PC to connect the PS4 controller.

*USB Adapter = 8Bitdo USB Stick / The product