Hollywood has completely changed over the years and can be a pretty fickle beast. The major stars who once captured our attention with their unique talents and uncommon looks might actually struggle right now. The industry simply demands very different things from its leading performers today.
Humphrey Bogart

Bogarts rugged face and world weary attitude made him a huge icon of 1940s cinema. Today casting directors usually look for younger guys with perfect smiles and chiseled jawlines to lead movies. His signature smoking habit just would not fit the superhero universe where everyone has to look like a polished model.
Peter Lorre

With his big bulging eyes and unsettling voice Peter Lorre became the ultimate movie villain back in the day. Modern movies usually want actors who can switch between being the hero and the bad guy. His thick Hungarian accent and smaller build would definitely limit his chances since studios want versatile people today.
Charles Laughton

Laughton had amazing theatrical training and he was absolutely perfect for playing larger than life characters. The movie business today focuses way too much on physical fitness so his heavy frame would probably get him sidelined. Modern audiences also prefer really quiet and natural acting instead of his intensely dramatic style.
Edward G. Robinson

This guy was the definitive gangster of early Hollywood with his tough guy persona and rapid fire speaking style. He was only five foot five and today Hollywood rarely gives leading roles to guys under five ten. The character driven dramas that showed off his raw talent have mostly been replaced by giant computer generated spectacles.
Ernest Borgnine

Borgnine actually won an Oscar for playing an ordinary looking butcher searching for love. His gap toothed grin made him super relatable but contemporary Hollywood does not really celebrate ordinary appearances anymore. His face told stories of hard work and that real working class vibe is something you almost never see on modern screens.
Wallace Shawn

Shawn had a diminutive stature and a bald head but he created amazing roles through pure intelligence and wit. His work showed how great talent and interesting conversation could carry an entire film. Today the market demands visual spectacle so his classically trained background would likely get overlooked for someone with a huge internet following.
Rod Steiger

Steiger was famous for his intense method acting and he was always willing to physically transform for roles. Today actors face pressure to stay camera ready year round so those transformations are huge career risks. His raw performances just would not fit the family friendly tone that big studios require for their massive investments now.
Don Knotts

He built an entire career on playing nervous characters who were just lovably incompetent and hilarious. His physical comedy relied on perfectly timed reactions rather than the crude jokes you see today. Modern comedy has shifted toward snark so his gentle humor would probably be considered way too safe for current audiences.
Marty Feldman

Feldman turned a medical condition that gave him protruding eyes into a legendary comedic trademark. Today Hollywood would likely view his unique appearance as a liability and they would probably steer him toward voice work instead. Modern studios love to focus group their comedies which completely eliminates the weird oddities that made him great.
Jack Elam

A childhood accident gave Elam a wandering eye that actually made him one of the most memorable western villains ever. His crooked grin created an unsettling presence but today the industry would just use computer graphics to correct his face. Modern casting uses strict parameters leaving absolutely no room for unique happy accidents like him.