Toulon Does any of that answer how/why she got her big break? How did she get noticed? I'm genuinely curious now and might have to go look for myself.
https://www.biography.com/people/barbra-streisand-9497402
I'll try to help you out here. For one, she's the highest selling female singer of all time. Why? Because people bought her recordings. Why did they do that? Maybe because they liked the way she sang. Why did they like her voice? Maybe because they have good taste in talent.
BTW, I think she has a great voice and was a good actress. So to help answer your question of why she became famous? Because a lot of people thought she had a lot of talent, both as a singer / entertainer and actress.
You brought up her looks. You could say she had so much talent that she overcame her looks. Some people become famous for being famous (i.e. the Kardashians) and some people become famous because they have talent. Streisand, Elvis and The Beatles would fall into the latter category.
"The statistics of Barbra Streisand's achievements are staggering. She is credited for creating dozens of gold- and platinum-selling albums, and is regarded as the top-selling female artist of all time. Streisand has had No. 1 albums in each of the last four decadesāthe greatest longevity for any solo recording artist. She is second in the all-time charts, ahead of the Beatles and The Rolling Stones, and exceeded by only Elvis Presley.
Streisand has sold approximately 250 million records worldwide, and is the only artist to have earned honors from all the major award institutions, including two Academy Awards, one Tony Award, five Emmys, 10 Grammys, 13 Golden Globes, a CableACE Award, the University of Georgia's George Foster Peabody Award and the American Film Institute's Lifetime Achievement Award. In 2015, she was further honored as a recipient of the Presidential Medal of Freedom."