Butterick’s Practical Typography states that “In justified text, hyphenation is mandatory.” It’s important because long unhyphenated words can result in short lines mid-paragraph that appear stretched.
Hyphenation opens up a big can of worms. How would authors signify where to insert hyphens in long proper names? How would authors disable hyphens in words that shouldn’t be hyphenated? Chrome doesn’t support the CSS
hyphens: auto attribute on Windows or Linux, so hyphens wouldn’t work there.
In my experience, full justification with automatic hyphenation is hard to read for non-native speakers, as they have to do a lot of mental gymnastics to glue hyphenated words back together and figure out what they should mean.
I’m willing to consider it when Chrome supports automatic hyphenization on Windows, but until then, I think it’s a bad idea.
One closing thought from Butterick’s:
Justification is a matter of personal preference. It is not a signifier of professional typography. True, most (but not all) books justify the text. But most major U.S. newspapers use a mix of justified and left-aligned text. Same with magazines.
Keep in mind that the justification engine of a word processor or web browser is rudimentary compared to that of a professional page-layout program. So if I’m making a word-processor document or web page, I’ll always left-align the text, because justification can look clunky and coarse. Whereas if I’m using a professional layout program, I might justify.
But the choice is yours.