The Gemara specifically says that if there isn’t another route, you can pass by the spot where women are washing their laundry, although they roll up their sleeves in the process.
Does the Gemorah say these women rolled it up uncovering erva (i.e. above the elbow) or just rolled it up higher than usual but not showing any erva? If these women weren’t showing erva (in public no less), then you brought a bad comparison.
Secondly, using your logic you could equally apply it to permitting going to a restaurant where they have improperly clad woman serving as waitresses.
And how is it avoidable from hearing the erva (kol isha) in the first case? Even without paying attention you hear it; in the second case, by passing an improper scene you have better control in not looking at the erva, than you have in not hearing erva.