First of all, I dont think many people here know what they are talking about becasue some of these opinions are just completely not true.
About the money issue- Its not 20k because you dont have to go home for pesach (I didnt and neither did about 35 other girls in my seminary) and you can get plenty of scholarships (I did even though my father makes over 200,000) and most girls contribute some of their own money for seminary(I did and so did my roommate who paid for everything that the scholarships didnt cover).
But if you will argue and say you know people who did spend 20k let me tell you that had my parents spent 50k it still wouldve been worth it. Of course this isnt true for everyone, but each parent should know their own daughter and while some girls belong in EY others really dont and just get worse.
I definitely dont think that it should be a given that everyone goes. But let me tell you about my experience.
Firstly, the learning was on a totally different level than high school. I can say without a doubt that what I learned in four years of high school doesnt even come close to what I learned in a month of seminary.
There is also the advantage that you are away from family and friends who know you well and can start life anew and grow without them bothering you and without wondering what will they think if I start doing this and this to improve myself.
WIY- You started another post about how this generation is lacking emunah. I can honestly say that while I never heard a class on emunah and bitachon in high school, in seminary we had a subject devoted to Chovos Halevavos where everyones hashkafos drastically changed for the better. I would not be the person I am today, married to the ben torah that I’m married to today and be able to face the challenges that I have, had I not gained such a strong foundation of emunah and bitachon in seminary.
No question about it- Seminary in EY is necessary for those who will benefit.