The Keyboard and Trackpad on my 13" Early 2015 MacBook Pro (currently running macOS Mojave 10.14.4) stopped working completely. I have tried everything, resetting SMC, NVRAM and such. Stayed with Apple Support call for hours, nothing they did could help me out.
I had a Boot Camp partition on the time, and these things didn't work over there either. (I'm using an external keyboard and mouse).
A few weeks ago, I accidentally nuked my entire hard drive and had to reinstall macOS from scratch (tiny bit hopeful that this would solve the problem). In the process I installed Lubuntu, and the weird thing is that my internal mouse and keyboard work over there! They just don't work when I am running macOS. (Refind also suddenly stopped showing up on boot but that's another problem)
Following are the specs of my system: