Unfortunately they don't support shelling out or running static binaries, which makes Cloudflare worthless if you want to run other programming languages like Crystal, Ruby or Python, or do OpenCV stuff, which you can readily do (with some difficulty) in Google Cloud Functions and in Lambda. You are stuck in pure js land with Cloudflare workers, though they are still awesome for this speed increase.
disclaimer: I have 27 Google Cloud Functions doing native stuff atm, about 70% in Crystal, 15% in Ruby, and 15% in Python.