From https://webkit.org/blog/16547/better-typography-with-text-wr...

"While support for pretty shipped in Chrome 117, Edge 177, and Opera 103 in Fall 2023, and Samsung Internet 24 in 2024, the Chromium version is more limited in what it accomplishes. According to an article by the Chrome team, Chromium only makes adjustments to the last four lines of a paragraph. It’s focused on preventing short last lines. It also adjusts hyphenation if consecutive hyphenated lines appear at the end of a paragraph."

The article goes on to talk about how it's up to the browser (and not necessarily permanent) about how to handle the setting, and furthermore a new value was agreed upon to do what Chromium was doing, called "text-wrap: avoid-short-last-lines".

Here's the article on what the Chromium version does: https://developer.chrome.com/blog/css-text-wrap-pretty/