Once upon a time (back in the days of Old English) male humans were called weremen and female humans were called wifmen. Wereman meant “man” (this is still seen today in words like “werewolf”, which of course means “wolf man”) and wifman meant “wife of man”. The -man suffix relates to human.
Over time, the were part of wereman was dropped and men simply became men, while wifman evolved into the word woman.
When you change the word “woman” to “womyn” you are taking the part that relates to being human and removing it because you arbitrarily don’t like it seeming like “man”, while keeping the part that devalues women to simply being wives.
Learn the history of words before deciding what is and is not dehumanizing.