My main problem with Apple Maps is how bad the driving directions are.
The maps themselves are much improved here in the UK, but no matter how good and detailed they are, the directions when driving are almost always hopelessly bad. No matter if you select a superstore, a shopping mall, a hospital or a cinema, Apple Maps will never get you to that location's car park, but just somewhere in the area. The end point is almost never the same with the actual location as shown in the map, but more or less random. Sometimes a busy road adjacent to that location, sometimes a couple hundred metres away, sometimes even further. Once I drove to a particular vintage furniture shop I never visited before, and following Apple Maps I ended up in an empty car park almost 20 miles away from where the shop was placed on the map.
And no matter how many times you submit feedback in the app for a particular location, explaining that their driving directions are completely wrong, they are almost never corrected. Not only are they not actively improving the directions themselves, but even when they have users complaining and pointing them what is wrong, they still don't do anything about it.