What causes iPad charging port defects?

I had a problem with my iPad charging port on my first iPad Pro-brought it in to approved service center-they replaced my iPad. It was still under warranty but now my replacement has the same problem but is no longer under warranty. I’ve read of other people having the same problem which leaves me to believe that there is a manufacturer defect with this problem. Can just the port be replaced in house and how long would I be without my iPad? Has Apple taken responsibility for this issue?

[Re-Titled by Moderator]