I'm not gonna overreact here, but I've been saying G5less Luffy is already on par with any top tier as seen in the Kaidou fight. Which is why I've been questioning why Oda is having Luffy spam G5 this arc.
Luffy being in G5 to start was a red flag, he doesn't last long in that mode, so Oda has to have Luffy dominate in that short timespan otherwise it diminishes the mode and the need for a timelimit.
This doesn't say anything about any top tier other than Luffy is simply this strong now, he has every single power up you can possibly have and now a god fruit ontop of it. Kaidou already placed G2/3 Luffy > Big Mom a fellow Yonkou, that was already when I came to terms with Luffy just being that strong when he doesn't even need G4 to be above an OG Yonkou.
I'm on record saying G4 Snakeman should be capable of defeating Kizaru prior to this arc. But it looks like Oda isn't interested in fights this arc which is why Oda has Luffy trotting around in his peak taxing state, looking like a full blown escape.
This is also why I'm on record saying Akainu has to fight Luffy very soon, he's out of his depth. It's really looking like only Teach who can shut off his df is a threat, and that's only in theory cause even Teach looks weaker than Luffy atm.