Well i think turbo engines are more needy of guages for the following reasons.

on a n/a car oil pressure usually isnt a problem, and the oil pressure light is ok !

on a turbo car, there aer oil feed/return hoses which are prone to leaking/bursting and the loss of oil pressure is very fast, so an additional guage is probably wa wise move!

boost guage helps if the car isnt going proper, overboosting, can see how much and if it is, etc

AFR guage, can tell if the car is getting the right fuel-air mixture, again not much of a prob on N/A cars

there not Essential, but all help and keep peace of mind to tuned cars which are more prone to breaking IMO