Game Cheats and Cheaters ruin things for everyone else in online play and obviously Esports Competitions.
They also ruin things for others interested in applying graphical enhancement post processing filters, for better looking game experince, not intended or used for cheating.
Blanket bans are applied to the use of such filters in tools such as Reshade (https://reshade.me/) or Nvidia built in GeForce Experience Game Filter Effects (which can load and use ReShade Filters directly) to all online situations in some games.
Some cheat detectors try to ban you if they even detect ReShade has been installed even though the standard ReShade release prevent some filters and features turned when online because they could well help cheaters to do things like "see through walls" etc.
I am not sure if AMD Radeon Image Sharpening (available as CAS.fx filter in ReShade, and used along with Sapphire Trixx Boost software) is generally seen as a "cheat" yet?
RIS might be seen as a cheat in some in some situations for example if resolution downscaling and RIS are used at 1080p increase FPS performance (and therefore lower latency ) but give the same visual clarity as native 1080p.
That could be seen as a competitve advantage versus other players in some situations.
Then again - people with better/more modern CPU and GPU are also at an advantage versus others...