Sean William Scott became a household name for his role as "Steve Stiffler" in the American Pie franchise. His role was a gift just as much as curse: on one hand he became extremely famous for his role as "Stiffler", but on the other, he couldn't get rid of the role itself. In 2011, he admitted himself to a clinic to seek help with personal and health problems.
Stephen Collins's roles as "Eric Camden" in 7th Heaven won him major international success back in the day. Sadly, in October of 2014, a few recordings were released where Collins admits to sexually harassing teenage girls. Ever since the infamous scandal, the offers have drastically disappeared...
Freddie Prinze Jr. got his big breakthrough in the movie I Know What You Did Last Summer. By sheer fate, the actor actually met the mother of his future children on the set of the movie. All we see of him nowadays is the occasional guest role on TV.
During the early 90's, Culkin was probably one of the most recognizable child actors of the decade. His role in Home Alone won the then 10-year-old millions upon millions of dollars. Sadly, the fame was too much for Macaulay to handle which led to no further success and a pretty nasty drug problem. He hasn't been cast for anything major since then.
Mel Gibson has been super successful as both an actor and a director throughout his career in Hollywood. Shortly before the premiere of his movie Apocalypto, he was caught driving under the influence which led him to uttering antisemitic slurs on camera. This led to people boycotting his movies and the actor in general. Nowadays he tends to stay behind the camera, but looking at the bright side, he got nominated for an Oscar for directing the movie Hacksaw Ridge back in 2017.
Oscar-winner Catherine Zeta-Jones was THE biggest star in Hollywood during the early 2000's. Like many actors, she just couldn't handle the fame. While she regularly discusses the topic of older women not having enough opportunities in Hollywood, the lack of her own role offers is probably due to her bipolar disorder.