InDesign already does this (as does quite a number of other software) and it works remarkably well. There is rarely a situation in which manual adjustment improves the typesetting and the automatic solution i definitely always good enough.

A manual solution is possible but not very practical, as was also mentioned in the article. Especially when the web design is responsive, such manual adjustments are problematic. But HTML is (luckily) also very flexible and neither font size nor the font are guaranteed to be constant, making a manual solution break horribly in e worst case.

CSS desperately needs feature parity with something like InDesign when it comes to typesetting. Adding stuff like this is obvious, something those working with layout programs had at their disposal for a long time.