It's the nexus of visual culture, history, politics, linguistics, technology, business... as a visual artist, type has a purity of form that has a Zen quality.
The ramp isn't meant to be different weights. The left is the original Material Design 1 ramp that uses tracking and static font weight tweaks to try to approximate an even color. The right is an actual even color.
Oh wow- the thread shares a new spec that does exactly this. Incremental Font Transfer[0] which “…allows clients to load only the portions of the font they actually need which speeds up font loads and reduces data transfer needed to load the fonts.”