The issue is...

• water quality
• water pressure

They can be a replacement for toilet paper if you have both water quality and adequate water pressure. Otherwise, you could contract a pathogen both superficially and internally via the anus, which could lead to intestinal issues and even cancer.

Lack of water pressure could lead to inadequate cleaning.

Many countries lack both water quality and water pressure, and it is difficult to self-service in such countries. These countries also lack sufficient sewage systems to handle flushing of toilet paper.

These are not an Arabic or middle eastern invention, they are a French invention, used by French nobility. They are a European invention.