Someone decided to compare Apple to oranges. Jesse explains:
First, they are not the same. One is a traditional touchscreen tablet (iPad Pro) and the other is a traditional cheap-assed PC notebook with an optional and crappy keyboard with a touchscreen that seldom gets used (Surface Pro 6).
One is a tablet that can accomplish PC-like tasks, and the other is a PC notebook with some tablet-like functions.
They are not the same.