They’re clearly rivals though, Oda has always used that dynamic. Law’s bounty is always on par with Luffy’s with every major update — his final bounty will be in the 5B range (same as Ope ope). Luffy only really got ahead in Wano since he received 2 major powerups. Kidd and Law will catch up, even Zoro and Sanji will catch up.
The script just flipped, this is Kidd and Law’s Sabaody. They will rapidly progress power-wise for the final war.
Ofc feat-wise, Luffy will still look ahead but portrayal is portrayal. BM was supposedly a rival to Roger and more or less on par with Kaido. There’s no feats that backs that up but you can’t deny her portrayal.
Not really Luffy has been having the royal treatment compared to the other Supernovas with far more many and better feats, him defeating Doflamingo, several Yonko Commanders, being called a Yonko by the press and public, defeating Kaido and being far stronger, having his own fleet of allies and countries under his official protection and even being the messiah/god of One Piece.
Law and Kid being rivals is just marketing, at best they are just other allies to Luffy. And they have nothing in common with Whitebeard and Shiki anyway in terms of personality, goals, and crew's numbers and power.
And I wouldn't bring Big Mom's portrayal up because of how abysmal and disastrous of a job Oda has done of portraying and treating her in the second half of WCI and even worse during Wano arc, save for her clash with Kaido.