Most home contractors sub everything. Roofing goes to one crew, siding to another, trim to a third. The carpenter who knows what a square corner looks like is rarely the one swinging the hammer on the house. The buyer becomes the project manager between four trades and brokers the warranty hand-off whenever something goes wrong at the seam.
On the insurance side, it is worse. Storm-chasers show up after a hailstorm, sign as many homes as they can, file the claim through whichever supplement mill they are partnered with, and disappear before the supplement gets denied. The homeowner is left holding a half-finished roof and a carrier who already paid out.
And when the leak comes back six months later, the original contractor does not answer the phone — because the leak was not a roof leak. It was rotted decking, a kickout flashing the original installer skipped, or a window seal nobody inspected.