There's a difference between user-swappable and battery-as-a-service. There is a company called NIO that seems to be successfully doing battery-as-a-service in China right now and is trying to expand this platform to Europe. They're also in talks with other manufacturers who seem to be interested in developing a common standard to make the batteries interchangeable so the stations can service other brands too.

There may be safety concerns (e.g. if I understand it correctly, the swapping process is fully automated and the car locks the doors and takes over steering, so I'm not sure how this deals with emergency scenarios where the driver might need to leave the car or intervene) but as far as the driver is concerned they never touch the battery so the risk of accidents from improper wiring is significantly reduced.