Does "Grit" in writing only work if the author has lived it?

There is an age-old debate in the writing world: Write what you know. On one side, we have authors who conduct "research" from the comfort of a café. On the other, there are those who develop their scripts and novels in their heads during 16-hour shifts of grueling manual labor or during years of isolation.

I’m curious about your take on authenticity in literature and screenwriting:

Authenticity vs. Research: Can a university-trained writer truly capture the soul of a courier, a baker, or a laborer without ever having felt that specific type of exhaustion?

The "Dirty Fingernails" Advantage: In today’s market, does raw, lived experience (e.g., time served, hard manual labor) carry more weight than technical perfection from a creative writing program?

The Cliché Trap: Where is the line between portraying a "harsh reality" and falling into misery-porn clichés?

I know of a writer currently pitching a sitcom about the very industry they are working in for 200% effort every day. We’ve been debating whether the "dirt under the fingernails" on the page is a genuine competitive advantage or if the industry still prefers a more "polished" version of reality.

What do you think? Does the sweat have to be real for the prose to work?