I'm only speaking for equipment interesting in voltage measurements.
Multimeters, oscilloscopes and conventional lock-in amplifiers seem to have mainly input impedances of 10 MΩ. I understand the need for a high input impedance to stop drawing of current and avoiding the voltage divider effect. Why don't manufactures opt for input impedances of higher ranges in their design?
Wouldn't a 100 MΩ input impedance multimeter be of more value for the customer?