Why did wings start to be made with aluminium skin instead of fabric?
Wings and fuselages are subjected to twisting loads as well as bending so they need to be torsionally stiff.  Prior to aluminum, the options were to make the wing/fuse with a frame of spars and ribs with fabric to provide the aerodynamic contours, braced with struts and/or wires to provide the torsional stiffness as well as resistance to bending, or, to do away with the struts and brace wires and make a monocoque structure (like an eggshell) with a plywood skin to provide torsional stiffness (with the spar beam inside for bending).  If you wanted to go fast, you had to do away with all the bracing so plywood monocoque was the way to go.
When &quot;duraluminum&quot; came along after WW1, it was realized that as well as replacing sitka spruce for spar beams and ribs, it could also replace plywood for a stressed skin monocoque structure.  You could build an airplane in the 1930s using plywood stressed skins bonded to wood ribs and spars, or aluminum stressed skins over aluminum spar beams, and have pretty much the same performance.  You could make your egg about of plywood, or aluminum sheet, and it was pretty much the same egg.
There were so many manufacturing and durability advantages to aluminum (no glue, no wood rot etc etc), it was a no brainer to switch, once the metallurgy started to become understood well enough to use it as an engineering material, and plywood skinned wooden airplanes faded quickly.