Is 纟 obtained by simplification of 糸 ？
纟 derived from 糸, which is the silk. (looks very like)
Like many other simplified Chinese Characters, 纟comes from 草书, such as

訁 -&gt; 讠
飠 -&gt; 饣
糹 -&gt; 纟
釒 -&gt; 钅

most of the characters with 纟are related to textiles ( 纺织品 ) , such as
“丝”、“线”、“经”、“纬”、“绑”、“纹”、“纷”、“纱”、”“绞”
refer to: https://baike.baidu.com/item/%E7%BA%9F/8457525?fr=aladdin