That's the thing, it's like what I mentioned in the Bow Wow thread, it's all about your reputation amongst your peers.
Cardi B just seems like a more positive and energetic person than Nicki Minaj.
The worst thing you can be in the industry is cutthroat. There's a level of confidence, no doubt, but you want to give off the impression that you're easy to work with and have good intentions for your peers and younger artists. If people act shady toward you that's cool, don't throw them under the bus unless you need to defend yourself (without overdoing it). Just keep it moving because if that's how they are then it'll come to the surface anyway (because they'll probably do it again to somebody else) and your reputation won't be tarnished. Word gets around quick and people talk.
But if you keep throwing shade, then no younger stars will want to work with you and the industry thrives on younger stars. That's how many artists who are older stay in the spotlight, they help the younger artists out and the younger artists give them some shine. There's mutual respect.
It's no different than any other job. At the end of the day they, like everybody else, are human and as humans we don't like to work with people who are cutthroat and overly competitive. Rather we like to work with people who will help us get better, are supportive, have good intentions and want to collaborate rather than compete. In other words, those who seek win-win situations for all parties. Nobody likes working with people who are only in it for themselves or have a serious chip on their shoulder (unless it's for a very noble cause) because it's toxic.