> Another point. We don't actually know how good the best climbers were throughout history. There's a clear upward trajectory to 19th-century British mountainee

> Another point. We don't actually know how good the best climbers were throughout history. There's a clear upward trajectory to 19th-century British mountaineering and its descendants. But how good were the best Incan climbers in 1350? Even through the early 19th century climbers were much better than given credit for, part of this is also how grading shifts over time. I've experienced this first hand, climbed some old "HVS" routes (fairly easy grade) established in early 19th century in wales (UK), only to find them in the low extremes by modern standards, maybe E2/3 (no this wasn't mere sandbaging), on top of which they were using heavy gear, unsafe gear and mountain boots! I have much respect for forgotten pioneers of climbing, they were much tougher than they appeared on the face of their accomplishments. We all have little jokes in climbing when conditions make routes harder like rain, cold, dirt, birds whatever, "oh this bird shit turns it into a VS / E12 today".. it's silly, but when applied generally, it's true - every aspect that is different can make the same climb significantly harder or easier for others, those pioneers probably were climbing E9 for them.