>>33765531Machamp isn't used because Gamefreak keeps forgetting to give it new tools to keep up with the meta. Yes, Conkeldurr has better stat spread but even in Gen 5, Machamp is still seeing use because his niche was somewhat useful and even won Machamp VGC Seniors twice since. In Gen 6, they were both UU. So there are instances that show both fighting type titans can co-exist in their own lanes.
The problems is not only did Gamefreak neglect Machamp competitively for Gen 7, they also nerfed confusion, indirectly nerfing Machamp's only niche that differentiates him from his peers, forcing Machamp back to Guts strat, which is done better by Conkeldurr.
If GF replaced Steadfast and gave Machamp a separate niche (i.e., a physical quiver dance coupled with say, Stamina or Defiant), Machamp will at least have some use. Or they should at least have adjusted Dynamic Punch's base damage (i.e., 120 BP just like Zap Cannon) to compensate for the confusion nerf.