Triton rigorously tests their subs in a pressure chamber far exceeding the design depth and there has never been an incident on one of their subs even down to the lowest ocean depths. They hold the record for one sub diving to the 5 lowest places on Earth.
However, their subs are not suitable for tourists since have only 2 seats and are far more expensive. Only one passenger can come down and the cost is probably >$1 million per dive.
Oceangate idiot was trying to go big and go cheap while ignoring the experts. It is an insult to even compare that clownshow to true engineered/certified subs.
Titanic depth — 12,500 feet / 3,800 meters / 2,100 fathoms