KISS...
hello.... IAS is the pressure at the pitot head.....
and is directly related to air pressure exerted on the structure.
It has a constant relationship to such things as stalling speed....
and should be closely related to any flutter values.
Any corrected values are great for navigation... and little else.
Uncorrected pitot pressure is therefore valuable!
An ASI showing a corrected value for TAS will show a different stalling speed with changes in density.... altitude, temp etc.
Back to the Mach...!