This has always been the case. I lived on a road that did not go through, Google and Apple said it did, people would argue with me and I would say 'I have lived here for eight years, go ahead I will see you again in twenty minutes'. The would come back twenty minutes later and be mad at me.
One day when I was really bored I looked through our city archives and found a map from the 1930's showing the road went through(proposed, never happened). No other map did including the current city map, or my paper map.
The problem is the way Maps determines routes makes a lot of assumptions but there's rarely, if ever, a human to correct it until it gets reported a significant number of times. It also tends to fine-tune the routes based on data from drivers. If enough drivers drive down a road and onto another road with Maps open, Google takes that to mean the road is open and the route connects.
In these kind of backwater, low population places, there often isn't enough data. Not enough people driving down these roads with Maps open, and not enough people that encounter a bad route bother to report it to Google. So no human ever corrects it.
Yet another example of how terrible Google makes its services by refusing to hire humans to manage these things.
Sure there are rough edges, but I've got to say Google maps is one of the most valuable tools I use, I used it more days than not, and it's free. I remember the days of printing out directions from MapQuest or having a whole map of the country you keep in your car. Modern map apps are kind of a miracle.
There was a story of a guy whose property had exits on either side. Google/Apple/whatever picked up on his data and everyone started using it like a public thruway. He said he had to put up an earthen berm and wood fence (losing his own access to one side).