And yet, that is partly a hip-hop myth deployed by gatekeepers. Cardi proves it’s a lie: The skills she has been deploying to hilarious effect in her other careers are exactly the ones that make her music so invigorating. Few artists of any kind are so visibly and infectiously enthused.

As a result, the appetite for her is insatiable, and the career milestones are coming fast and furious: co-hosting “The Tonight Show” alongside Jimmy Fallon, appearing on the covers of various magazines, announcing her pregnancy during a performance on “Saturday Night Live.”

She has also been the most reliable hip-hop guest star of the last 12 months, with appearances on G-Eazy’s “No Limit,” Migos’s “MotorSport,” Ozuna’s “La Modelo” and the remix of Bruno Mars’s “Finesse” — she has yet to release a dud. For someone who only started rapping a few years ago, that stylistic versatility is striking — it shows Cardi to be a quick study. And indeed, in a recent interview with Ebro Darden for Apple’s Beats 1, she spoke openly about wanting to improve as a rapper and working with a more experienced rapper and songwriter, Pardison Fontaine, to improve her technical skills. “I needed a little bit of help from breaking out of my box,” she said. “I need to learn how to flow a little bit easier and cleaner.” (There was some consternation online after an old video of Mr. Fontaine performing part of “Be Careful” recently resurfaced online. Atlantic Records did not make songwriting credits for “Invasion of Privacy” available.)

The hard work shows, especially in terms of her cadences, and her ease in adapting to various production styles. Her quick-jab rhymes aren’t particularly complex, but occasionally she gets off a delicious turn of phrase, like this one, from “Money Bag”: “These bitches salty, they sodium, they jelly, petroleum/Always talking in the background, don’t never come to the podium.”

The work of becoming a great rapper is something that’s rarely spoken about, but Cardi has been open about her education process, an implicit acknowledgment that her path to success has been unusual. It is one way rap stars are made today, and may be for the foreseeable future — not by triumphing over other rhymeslingers in Darwinian fashion, but by arriving to the genre as a fully formed personality, and then learning how to shrink-wrap that personality around beats.

This is a new paradigm, one that puts charm before bona fides. It is what happens when a genre is exposed to sunlight and expands beyond the internal logic that once drove it. But it’s not enough for Cardi to win on those terms — she wants to succeed on the old ones, too.