" it’s all just a educated guess." Primate cousin of humanity, giant form of known relic human ancestor. Heck I've even wondered about escaped pre civil war slaves. IDK. What I do know is right off the top of my head I can remember three stories of hunters shooting one and then standing over the body fearful of being accused of murder because of how human it looked like. And then burying it. Nobody ever stood over the body of a monkey and believed they might be accused of murder. Who knows maybe the stories are all BS. But what are the odds of nobody ever getting a shot off at one of them ? If not , then you veer off into some kind of bulletproof supernatural/interdimensional being
ETA If one actually goes out to shoot one. One must be prepared for the possibility that they are human. And if so , most people won't believe you shot bigfoot. Better make sure you bring a shovel.