This was my thought - someone should put a 1950's-1970s alarm clock on a meter, as well as a current cheapie alarm, and see how the energy draw compares.

Not all plastic is equal, it could be an excellent design for longevity. Plastic doesn't rust. As long as they designed the parts to be robust, and they used a good quality reinforced type of plastic, it might be excellent.

33 years, wow, so from the 70s... thinks a moment Crap, I'm old.