Gamescope is developed by Valve and none of these parameters gives you unfair competitive advantage. I've used gamescope for many years and never had an issue.
Gamescope does support Reshade effects, and I would not encourage enabling those.
Without adaptive sync is still better than native resolution without gamescope, so I'm not sure why you're so dismissive. I'm just trying to share a list of tweaks that made the experience better.
This might have been partly true 10 years ago. A large majority of his audience is probably adult now.