This problem also exists in Prague. We have donation bins for clothing here. Dozens of organizations are authorized to place them on the streets. Some are charitable, others purely commercial. People don’t really distinguish between who owns which bin.
Of course, both homeless people and rats get into the containers. Sometimes a homeless person even gets trapped inside and dies. Other times, firefighters have to rescue the homeless person.
But I'm not aware of any plans by the city to ban the containers. There will be municipal elections in Prague this fall. Perhaps Prague will take a cue from Vienna.
There are many problems in the world for which I see no solution. This is one of them.