Multi-line text via the 'shape-inside' property is a direct replacement for SVG 1.2 flowed text. SVG 1.2 never became a final W3C standard and only the Batik SVG renderer besides Inkscape provided any support for SVG 1.2 flowed text. SVG 2 is not yet a final W3C standard but SVG 2 flowed text has one very important advantage over SVG 1.2 flowed text in that it is easy to structure the SVG 2 text such that it will be rendered (almost) correctly by an SVG 1.1 renderer. This means that browsers which do not support SVG 2 text will still render the text. One disadvantage of using SVG 2 text is that it will not be editable as multi-line text in Inkscape 0.92 (it will still be editable as single lines of text).