The flip side of fame is that you can lose the love of the public at any moment, which can completely rock your career opportunities and your personal life. Which is to say, celebrities fall from grace all the time, sometimes for extremely valid reasons, and other times due to wild misinformation, petty rumors, or extremely human mistakes.
Since the attention span of the public is both short and rapidly changing, it's all too easy to lose track of all the former famous people who were quickly plunged into obscurity.
In a popular Reddit thread, people shared which celebrities got "canceled" that they still feel bad about to this day.
Amanda Bynes. From what I've seen she was abused by Dan Schneider at Nickelodeon studios for YEARS and a lot like Britney Spears is currently under conservatorship because of a total mental break.
Ahmed Best played JarJar Binks and nearly killed himself over how hated the character was
Edit: Here's a video where Ahmed talks about his experience, I found it quite moving https://youtu.be/qfNiSkd3HfI