There Is Nothing Intrinsically Evil About Washing Soda (Sodi
Just as with everything else much depends upon how it's used, in what amounts, and what type.
Housewives, laundry workers and anyone else has known for ages that base (alkaline) substances shift certains soils, oils and grease for cleaning. Many also found out from rough, hard, cracked and dry hands from being frequently in contact with the stuff in wash/cleaning water how harsh soda can be.
Most TOL and MOL laundry detergent powders contain far less soda than older versions, especially after phosphates were removed and makers had to find their way around. Modern enzymes, surfactants, Zeolites and other substances remove much of the need for large amounts of washing soda in detergents. IIRC versions of Tide powder are <40% sodium carbonate more or less. Inexpensive products such as Arm&Hammer of old (and maybe even today for all one knows) still contain lots of washing soda to provide cleaning action. The stuff is cheap and can even be billed as "green".