Whether the average golf can deal with fast greens depends on the green contours. Relatively flat green sure they/we can adapt. Rolling greens, turtle backs, etc it would probably be frustrating .
From a maintenance standpoint it's more difficult. The shorter the cut, the more it's rolled ( compaction) it opens the green up to more disease, weeds and pests and requires more frequent watering/ monitoring. The average course barely has the maintenance staff to get by week to week. They don't have the staffs that oakmont and others have let alone the depth of experience beyond the super and maybe the asst super
I was watching practice round at the Canadian Open on Tuesday and VJ Singh was trying to chip cross handed . I observed him putting cross handed
I don't know why people call it left hand low. Why not right hand high? Whenever I use this type of putting grip sometimes it feels like my top hand controls the putter more than bottom one.