“My pectorals; they are not strong enough to flap.”

cut to sad da Vinci in an ornithopter

Uh, no. A lot of things have changed.

Shingles are different materials, and they can now produce power if you really, really want them to.

Concrete formulae have changed to set faster and more consistently. Modern concretes are also much less corrosive to internal metallic reinforcement, the alloys of which have also improved.

Wood frames are chemically stabilized, and the geometry has changed to support increasing levels of internal conduits and wires. I even have a built-in pest-control system in mine.

Insulation is dramatically more effective and less dangerous upon exposure. Window glass has lower thermal conductivity and is less brittle. Some of it even borders on flexible.

Nail guns are now a handheld device. Even the nails themselves have changed, and there are specialized nails that can do everything from hold a roof on during a hurricane or come apart at a specified force.

None of this even begins to touch the advancements in adhesives and sealants. Environmental compatibility alone is leaps and bounds past the 1950s or even the 1990s.

Like it or not… “cApItAlIsM bAd” is a pretty hollow worldview.