No one believes you “must” have prayers from others in order to “finish the deal” while in Purgatory.
You might be better served studying Catholicism rather than pontificating about it.
Do you believe that your prayers for someone’s conversion are a “must”? Does God decide to save someone based on your actions?
I would think not.
Your prayers are not a “must” and do not denigrate Jesus.
Neither do mine.
I am not saying that the prayers denigrate Jesus’ sacrifice, just that the belief, the Belief, that somehow, having Jesus as my Savior will NOT get me to heaven, that He is not ‘purging’ enough, that there is no way He can clean us enough, we still neeed to have a stopping point.
THAT is what takes away from Him.