There's a difference breh, Drake has a fanbase, Flo Rida and Pitbull have listeners. This is quantified by the fact that Flo Rida's albums don't sell, and his last album was 5 years ago meaning he and his label know he'll lose money on an album release, because he doesn't have a devoted fanbase who will purchase his music and listen an entire album of it. Flo Rida is a strictly sports/party/radio presence, and he's carved out a very particular niche that doesn't rely on fans to get placements, but rather placements to get listens. "Social relevance" is the ability to get the world buzzing and at attention when you release a record or move around in public. You don't have to go outside your circle to know Flo Rida doesn't have that influence.
Also RTJ has a really dedicated fanbase comprised of hip-hop heads/hipsters. They're an indie act who came up off the strength of that fanbase and critically acclaimed records they've been dropping for years, and make money doing shows because they play the festival circuit which caters to their fanbase. Yeah they're a fringe underground act, but they actually have a degree of social relevance because they have a following.
And to get why Vince always books Flo Rida, you gotta understand music marketing and how brand association works. Flo Rida fits the marketing and corporate image WWE portrays. His music is always used for sporting events, TV spots, movie commercials, etc., because his music is seen as fun, safe (safe being a big part of it, people ask why WWE doesn't fukk with Wale when 100% of his songs have an explicit tag on them), youthful, and energetic. Plus his price tag probably isn't that high, since he likely doesn't do solo tours and generate gate from concerts because, as I said, he has no dedicated following who will attend these shows just to see him. So I get why WWE likes to use him a lot, but at the same time I think they're probably losing out on a lot of money by not booking more impactful artists. They had John Legend sing the anthem in 08, I think they can open the checkbook for Shawn Mendes or Selena Gomez to do 1 or 2 songs at Mania.
Oh, and you really think Flo Rida writes his own shyt


Most of the industry doesn't write their own songs, pop stars being the most guilty of that. Plus its not like he's writing the next Illmatic each round, its some simple dancy pop catchy shyt that he can hire any songwriter from his pub label to compose and pen. Just check his publishing royalties or even his Wikipedia writing credits if you really think he writes 100% of his content. I'd be willing to bet Drake writes more of his work and gets more off publishing than Flo Rida does.