And your bathroom stays clean and leakproof
Your bathroom is a wet zone: water vapour, splash water and run-off water create new wetness here every day. It is important to protect the exposed surfaces effectively. Why? It's simple: if moisture penetrates the masonry through porous silicone joints, for example, it can cause major damage. And that quickly becomes expensive.
DIN 18534 for waterproofing for indoor applications requires baths and shower trays to have special seals. Silicone joints are not enough. Installation to industry standards can only be achieved with sealing tapes or upstands.