Call To Prayer / I have a question

I have a question and look forward to reading your answers. I had another sleepless night and while I laid there trying to fall asleep I had this thought, ‘Why do we go to the alter for prayer at the close of a service?’ I don’t know why this thought came to me. Yes I was praying. I have a prayer board I made hanging next to my bed so when I cannot sleep I can pray for others. Then BANG! This thought just popped into my head. Why is it that we ask people to come to the front of the church with all eyes on them at the end of the service? I have served on a prayer team for the current church I am a member of and have served in this same department at previous churches and never had this thought crossed my mind. I have many times been heart broken when the alter of prayer remained empty, knowing that many are hurting lost, and have some kind of need, either for themselves or a loved one. So why am I laying in bed praying and hoping for sleep did I question why do we ask people to come to the alter with the congregation as an audience to pray? I started thinking how many do not approach because they don’t want every eye looking at them, passing judgement (this does not mean they are being judged but the fear of being judged and maybe even gossiped about). I thought about Jesus teaching us to go into our closet to pray, but then I also thought about the scriptures about going to the elders to have them lay hands on us to pray and anoint us. These thoughts may be nothing more than thoughts of a sleep deprived mind. But I would like to know if anyone knows when this part of a church service began?