Why was World War 1 referred to as hell on earth?

World War I was referred to as "hell on earth" due to the unprecedented scale of destruction, loss of life, and the horrific conditions faced by soldiers and civilians. Trench warfare led to brutal stalemates, where soldiers endured harsh weather, disease, and constant threats of artillery and gas attacks. The war resulted in approximately 10 million military deaths and countless civilian casualties, along with widespread physical and psychological trauma. The combination of modern warfare technology and outdated tactics created an experience of unimaginable suffering and chaos.