This is not a SFW instance. NSFW communities will be tagged, and efforts will be made to keep SFW communities clean, but proceed at your own comfort level.
There would need to be an evolutionary drive to develop that tech. And in a water world there’s little reason to. The main utilization of fire was to cook food. From there other developments occurred. That’s not a thing that hydrothermal vents would be good at or easily utilized. An aquatic species would literally be inside the oven they cook with, and for little reason. Sushi is a thing we eat now. You also can’t smelt metals underwater. So passing the threshold of utilizing basic tools is basically impossible.
But since most fire is ultimately used to heat water, couldn’t a form of technology develop based on hydrothermal vents?
There would need to be an evolutionary drive to develop that tech. And in a water world there’s little reason to. The main utilization of fire was to cook food. From there other developments occurred. That’s not a thing that hydrothermal vents would be good at or easily utilized. An aquatic species would literally be inside the oven they cook with, and for little reason. Sushi is a thing we eat now. You also can’t smelt metals underwater. So passing the threshold of utilizing basic tools is basically impossible.