Why not? Because it started out bad.... 7 years ago?
In the old days of Macromedia Freehand and Adobe Illustrator, each version would add features and updates that would make it slightly better than the other. I would use it until the other came out with their new version. It was a constant ping pong/leapfrog of competing products trying to win until Adobe ultimately won outright. In my testing, not once has Apple Maps leapfrogged to be the leading app.
Look at the previous coverage on this blog - https://www.justinobeirne.com/
"Apple completed the rollout of this new Maps experience in the United States and will begin rolling it out across Europe in the coming months."