I was thinking about all the way up until the computer revolution finally sunk into government. In most places records were handled by hand by one person, at best a handful, and the records were only as good as that person. Nobody proof read, errors were only found if somebody suddenly cared about that record. By and large these systems didn’t change between the 1400s and the 1980s, the big revolution was typewriters so we were no longer reliant on Millie having decent handwriting. And the lack of reliability spawned an entire culture of people and communities keeping their own record, the Family Tree in the Bible, wedding and baptismal records in the church. All those things genealogists rely on largely went in place because record keeping was so bad, and have largely gone away in the last few decades because record keeping is actually useful now.
My dad sold a ranch in 1961 and in the 1980s he was contacted because when the people he sold to began the process to sell it there was a little piece of it that was still in my dad’s name. It was pretty odd, he signed off on it with no issue to help them settle it because as he told the man he intended to sell him the whole ranch and it was just an error at the clerk’s office when it was recorded. I often wonder how much that used to happen years ago. The man was lucky my dad was honest and willing to just sign off on it to correct the error; it could have been a legal mess I imagine.