They are more accurate then both of those. Cloudflare tracks all data that runs through it...which is everything on your site. Google and other script trackers only track what the script picks up.
You can say that until your blue in the face but I'm saying that from personal experience from testing all three out over the course of 10 plus years.
It simply is more inaccurate as it tries to report to me 200 visits a day when the others report 1000+... you tell me based on that which one is wrong. :biggrin: