Yes, a GoPro is going to be different in many aspects compared to an APS-C mirrorless camera. These cameras are small but look big alongside a GoPro, they cant stabilize to near the level a GoPro can and are not waterproof.
GoPro vs Camera video comparison
Depending on what lens you use your footage will vary. A 12mm, 14mm or 16mm lens can come close to that wide GoPro view but you cannot match the 6mm focal length the Hero 7 Black has.
The Hero 7 Black has an aperture of f/2.8 you can better that with many lens going as open as f/1.4
For this comparison i used a pretty close match up with the very wide and open Sigma 16mm f/1.4 on the Sony A6500 with a GoPro Hero 7 Black mounted on top.
Both devices recording 4k at 30fps with full auto settings for both. These comparison videos have been down scaled to 1080p:
Amazingly the GoPro makes the wide 16mm lens look cropped in, The GoPro gets so much more scenery in the shots. The fish eye also makes objects appear further than they actually are.
Play to the strengths
Its these effects that make the GoPro good at what it was made for… action. Recording all of the scene, event, jump, run or whatever you’re doing even if it is not directly in front of the lens.
Secondly the stabilization is just so so good on the Hero 7. It is very much like what a gimbal gives. I was trying my hardest to hold the camera steady whilst walking but it still takes the bumps, whilst the GoPro footage looks like i was gliding.
OSS (Optical steady shot) and IBIS (In body stabilization) don’t do much or anything at all to stabilize walking footage, they work best for when you’re standing still and removing jitters rather than thuds.
The GoPro costs as much as the Sigma 16mm lens alone costs, No matter the demand, production and material costs a GoPro does not provide video or photo quality. The price is an indicator of this, The specifications are an indicator of this and the pure raw video and photo is an indicator.
A GoPro is an amazing device for its size, it can get steady video at high resolutions and frame rates but to say it is higher quality and captures more detail than a decent camera is wrong but its also not fair either.
The a6500 has double the megapixels of the Hero 7 Black, more than double the price. Quality comparison is never a battle here.
It is the massive difference in view points and the stabilization that shows, because simply these two devices are completely different.