Yes, that's true. The water that splashes off the body spreads throughout the bathroom. Some accept it and wipe it off with the rubber squeegee, others have a glass panel installed - one is enough then.
I absolutely agree. The heat loss will be noticeable at the latest in winter. Anyone who then showers hotter or longer has not won. So I would at least put up one wall or make sure that three sides are closed.
So we will also build a shower niche, it looks something like this: Nothing will splash into the bathroom, and the tiles are nano-sealed... no lime will stick ;)
If you choose an open shower, it should be done like my predecessor suggested, otherwise you will have the entire bathroom flooded. A shower niche can also be made relatively easily by yourself, and tiles have the same effect as a nano-sealing. However, such an open shower is not feasible everywhere, especially since bathrooms are usually designed quite small in new buildings.
I know this from the sports club and here we had open showers. These also have no side walls. You just have to make sure that the floor and drain slope is well calculated. I can also well imagine this for private use.
Being good in a club might work, but in your own four walls? For me, the heat loss would be too great. Also the constant moisture. Then you are just wiping and cleaning all the time.