macOS Catalina - Keyboard and Trackpad not working I have a Macbook Pro (early) 2015 and roughly 2 years ago, the Keyboard and the Trackpad stopped working. So I stopped using it.
Two days ago, I had the idea to try it again. And it did still not work (how unfortunate!).
Then, I tried to install Pop!_OS via USB and I was able to use my Keyboard and my Trackpad already during the installation process.
I friend of mine has sent me a USB stick with OSX Catalina on it to try a fresh installation. However, the problems are back and while trying to install OSX, I am again, unable to use my Keyboard nor the trackpad.
What could be the problem here? The hardware itself works fine for obvious reasons.
It seems that your issue is not with the MacOS itself but rather due to the hardware controller inside your computer. In such cases, you should reset the System Management Controller (SMC) by following the steps below:

Turn off your computer
Press and hold Shift + Control + Option (Alt) + Power Button for 10 seconds
Release the keys and let the MacOS boot up