> This approach is different to how many text layout engines approach this problem e.g. by adding "one word at a time" to the line, and checking at each stage if it fits.

Do you know why Chrome does it this way?

We found it was roughly on par performance wise for simple text (latin), and faster for more complex scripts (thai, hindi, etc). It also is more correct when there is kerning across spaces, hyphenation, etc.

For the word-by-word approach to be performant you need a cache for each word you encounter. The shape-by-paragraph approach we found was faster for cold-start (e.g. the first time you visit a webpage). But this is also more difficult to show in standard benchmarks as benchmarks typically reuse the same renderer process.