Why was Cicero considered a novus homo in Roman politics?

In Roman politics, the term novus homo (Latin for "new man") referred to an individual who was the first in their family to achieve the rank of consul.1

Cicero was considered a novus homo because he lacked the ancestral pedigree typically required to reach the highest levels of the Roman government. While the Roman political system was dominated by established noble families who followed the cursus honorum—a traditional succession of offices—Cicero rose to prominence through his own merits, particularly his exceptional skill as an orator and his success in the legal courts. Despite his family's lack of prior consular status, his brilliant legal defense of Sextus Roscius and his subsequent career as a quaestor and praetor paved the way for his election as consul in 63 BCE.234