That's not entirely true. On the same resolution there's not a lot between them, I have made guesses at which camera took which footage and been wrong. I've seen some stunning Hero4 videos, look incredible, and I've also seen some that look like they were shot on a 1980s VHS camera.
In the current range of cameras out there, the GoPros offer higher resolutions that the Drifts, but above 1080p60, you're in to a limited reach of who can watch the better resolutions. As I've said before, what YT can offer (like 4K) is pointless as not many have 4K displays (they might have a TV, but how many watch YT on TV?), and a good number of people watch YT from a mobile device, phones can barely do 720p some tablets can do 1080p, and pretty much all laptops can do 1080p.
Best thing to do to make the comparison is to look for comparison footage between the two both on and off YouTube. YT compresses the hell out of videos, so for a true picture, you need to see that footage. You should also look in to how you edit and how you export your movies as well, this will also have a bearing on your footage.
I'm not suggesting one way or the other here, I have Drift and GoPro, I think both are comparable at 1080p30, base your purchase on budget, requirements and also on how you want to use the camera. Drifts have the better form factor for helmet mounting, but you can't (easily) chin mount of chest mount a Drift, GoPro win on that one.
