Washing clothes

i have washed majority of the clothes friends and relatives handed down to me for purposes as their baby already wore them and what not, i'm skeptical on washing all the new outfits mainly because THERE ARE SO MANY, and i don't want them to look worn already after a wash. i know they do have more sensitive skin which is why it's recommended BUT i have also been told by other mothers in my family they didn't with their 2nd and 3rd and they were fine due to baby clothes being handled differently and washed differently pre- shelf life... suggestions? is it truly necessary? also blankets and swaddles as well, necessary or not?