The average person, even “handy” ones, have no idea that they cannot “build” things with sheetrock screws. Sheetrock screws are low grade steel, not hardened, made to hold a piece of sheetrock on the wall with at least 30 other screws 16” apart. If you ever used sheetrock screws to put wood together, i.e. lumber, you have likely experienced the screws shearing off. If you are in a survival situation having the screws shear off can be trouble.
There is a solution, structural screws. Structural screws are almost as thin as sheetrock screws but made under stringent engineering standards. Made of hardened, high quality, heat-treated steel. They are virtually free of shear-offs. They are more expensive than sheetrock screws but are as strong as conventional lag bolts. Fortunately, where lag bolts require starter and pilot hole predrilling, structural screws do not.