I successfully removed Swiftkey and other bloatware on my XZ2c without root access.
It involves a cable connection to a PC and using adb command line interface. I now use an old Jellybean keyboard apk which I've had stored on my PC for about 5 years. It still works on my new phone in 2019. It has hardly any permissions, especially no internet permission. It is a swish keyboard, it will delete an entire accidental word with just one backspace tap, I can even move the cursor around with the volume buttons on the side which I love. My second keyboard is Hackers Keyboard only for Ctrl-C Ctrl-V functions without internet permission. Make sure an alternative keyboard is installed first before removing your only keyboard to avoid a predicament. Anyway, Here's the tutorial link: https://www.xda-developers.com/uninstall-carrier-oem-bloatware-without-root-access/