My tip, which seems to be working for me so far: I upgraded from a 2015 to a 2018 a few months ago, and _immediately_ added a silicone keyboard cover that I got

My tip, which seems to be working for me so far: I upgraded from a 2015 to a 2018 a few months ago, and _immediately_ added a silicone keyboard cover that I got on Amazon for $8 or so. It's really thin and doesn't bother me, but the key thing is that it keeps everything out of the keyboard. So far, my keys continue to all work just fine. It could be luck, but it could also be that no dust or anything is getting trapped in the butterfly switches. I will give the disclaimer that much of the time I'm typing on a bluetooth keyboard, but I still get quite a bit of use out of the built-in keyboard as well.