Adjectives get a hyphen because it clarifies their position in the sentence. I’m a proofreader and I will absolutely fix it if you leave it out.

there are times when punctuation is actually useful for clarification!

“Printed writing is very much design-led these days in adverts and Web sites, and people feel that hyphens mess up the look of a nice bit of typography,” he said. “The hyphen is seen as messy looking and old-fashioned.”

I see the dictionary editor they quoted is still fighting back.

That’s a sweet ass-car