Hello! Author here. When I say absolute positioning, I mean it in the CSS sense (as in position: absolute) to contrast it with CSS Normal Flow, Flexbox, Grid, Floats etc.
While it's true that SVG allows percent positioning and foreignObject with HTML inside, this does not help us for the task at hand: Positioning shapes/text in relation to other shapes/text. This is out of scope for SVG to my knowledge, while it's the natural domain of CSS.
Almost all of our charts have text labels of different size. In many charts, we measure the text with measureText() on a canvas first, then compute the SVG positions manually. Or we have HTML/SVG hybrids where we measure the text using getBoundingClientRect(). This two-stage measure/layout process is what we seek to reduce.
While it's true that SVG allows percent positioning and foreignObject with HTML inside, this does not help us for the task at hand: Positioning shapes/text in relation to other shapes/text. This is out of scope for SVG to my knowledge, while it's the natural domain of CSS.
Almost all of our charts have text labels of different size. In many charts, we measure the text with measureText() on a canvas first, then compute the SVG positions manually. Or we have HTML/SVG hybrids where we measure the text using getBoundingClientRect(). This two-stage measure/layout process is what we seek to reduce.