Because “minimum wage” is the least employers are forced to pay, it must be a wage people can live on not one that can’t meet basic needs..
Minimum wage is the base that other wages are set from. If you are earning above “minimum wage” be grateful to those that went before you because they took action, negotiated, put structures and levels in place to ensure skills were recognised and got you the higher wage.
Minimum wage is also used as a basis for welfare payments like pensions.