Two of the most famous were Mickey Rooney and Elizabeth Taylor! Rooney was the #1 box office draw of 1939 and both would marry 8 times although Taylor married Richard Burton twice! Now while Taylor grew up to be both beautiful and screwed up! Rooney’s short stature helped him to play younger roles than he really was.
Not unusual that some kids are cast in movies because of their unconventional looks but as they grow up their looks can become interesting and as a result they find less work in Hollyweird! Recently a former Asian kid actor was complaining that there were not enough roles for Asians implying a racial bias. But maybe his adult looks were no longer cutting it in Tinseltown!
And that is all I’m going to say about that!