Limited experience (Former brakes engineer) but I would guess that tube tyres are cross ply to reduce the amount of wire which stores heat, reduce the weight (as the tube is adding more) and make the sidewall pliable enough to get on and off with levers.
Don't forget there are manufacturers that go for the worst possible combination too. Tubeless shape rim drilled through for spokes and running a tube. You get the heat and repair hassle of the tube but keep the need to find a bead breaker. All about getting you into their boutiques as a Sunday morning alternative to Starbucks. I have seen a BMW G650 stranded with exactly this issue, can't patch it, can't plug it, call the RAC and get hauled off to go shopping.
Andy
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