Would be interesting to compare weight of frames: aluminum to steel.
Just weighed a steel frame and trussrod fork, similar to that of the bike shown below, ~12.5lbs.
This bike gets on ~20mile rides fairly often, not just "cruising":
1950s Monark "Special Cruiser" (middle-weight) frame and original Monark spring fork.
Bike weighs 34lbs on the nose as you see it. Doesn't sound light but it's ~1/2 of stock
Rims are 36h Campagnolo Mirox, Sachs 2spd Duomatic, cartridge front, DT 15g, alloy nipples, Continental Top Touring 2000 tires.
Weight savings over stock wheels/tires is nearly 6lbs, with the addition of a second gear