Density of automation equipment is all well and good, but it comes at a price of being difficult to maintain. If a tool or a robot breaks in some way (and any FMEA will tell you about the myriad of ways that can happen) then people will need to get into the cell and fix it. If you need to remove a robot, gripper or fixture - well, that's going to be difficult if you've landlocked everything by packing the machinery in so densely.
Vision systems for handling are great idea, but they are a nightmare to set up and to keep clean, especially in a welding shop.
Robots that repair the looms of robots around them. Fantasy, and it will continue to be fantasy for a good while yet.