Very experienced people die. Is diving more dangerous than we perceive?

A few days ago a very experienced diver, instructor and course director with a student went missing on a dive in Blue Hole, Dahab. Only student's body has been recovered from the bottom yet. They were doing a 'simple' by his metrics technical dive with max depth around 55m. He regularly dived to 100m+, taught people how to do it, had over 15 years of experience as an instructor. That's unbelievable. What could go wrong? Unfortunately, people who 100% know the answer can't tell it us anymore.

He left notes about multiple aspects of diving in internet under the name which is translates as "diving is simple". Well, maybe it's not in fact? Not simple at all? Even best people die. Nobody can guarantee that a dive will not end like this.

Many agencies convimced us that diving is safe. I convinced myself that I'm following rules and thus nothing will go bad. Probably it's a time to rethink it.