People seem to have forgotten the boom of prefab/modular houses in the 1960s/1970s. It turns out after the cost of delivery and final assembly on location you lose out a good chunk of the efficiency of the factory line production.
The biggest innovations to construction are probably to be had in better/faster/easier plumbing and electrical connections, making it faster and more reliable to install all the fixtures. Being able to plumb and install a whole bathroom in a couple of hours instead of most of a day while reducing the odds of needing rework would be a decent boost. We've seen some improvement in this already though with things like PEX and Wago, I imagine even more modular designs can improve this even more. The challenge with this is actually getting adoption and approval for some of this stuff.
The biggest innovations to construction are probably to be had in better/faster/easier plumbing and electrical connections, making it faster and more reliable to install all the fixtures. Being able to plumb and install a whole bathroom in a couple of hours instead of most of a day while reducing the odds of needing rework would be a decent boost. We've seen some improvement in this already though with things like PEX and Wago, I imagine even more modular designs can improve this even more. The challenge with this is actually getting adoption and approval for some of this stuff.