For extra context: that "3× deeper" makes costs seriously explode. People do know how to engineer for that depth, but it's a lot of effort and there's pretty much no commercial market. For shallower stuff there's oil rigs, deep-sea cables, seafloor mining, even just tourism… but at some point it just peters out and only research vessels tackle the depth.
(source: friend of mine works at a UK university doing deep-sea vehicles)
(Their vehicles don't even go that deep, but again that was the point I was trying to make… even in research, the very deep stuff is rare and a "big project" that ends up fanned out ⇒ MRIL made only the cameras for a 4km vessel…)
For extra context: that "3× deeper" makes costs seriously explode. People do know how to engineer for that depth, but it's a lot of effort and there's pretty much no commercial market. For shallower stuff there's oil rigs, deep-sea cables, seafloor mining, even just tourism… but at some point it just peters out and only research vessels tackle the depth.
(source: friend of mine works at a UK university doing deep-sea vehicles)