[worldimperator]

> Lots of fonts have numerals that are the same size/location as the rest of the text.

Actually there's not a 'rest of the text' that is homogenous, unless it's completely uppercase. In normal body copy it's a rhythm of ascending and descending letters, and to that those numerals are meant to fit.

The meaning of 'Lining Figures' is numerals that are spaced proportionally (the opposite of their tabular version). They are a good option in technical texts (as those set with LaTeX typically) where you want to integrate numerals, but still have them stand out. They are also the default numerals in many digital fonts, even if there are the 3 other options as well (it's a 2x2 system of proportional vs monospaced and text numerals vs lining numerals).