The thing is, Luffy becoming PK HAS to happen for the sake of the story. Fuji being essentially just a Revo in disguise doesn’t need to happen.
Y’all should ask yourself why Fuji isn’t already a Revo despite him being well aware of how awful the CDs are. Fuji might despise the CDs, but overthrowing the WG would result in piracy becoming much more rampant and unchecked due to a shortage of Marines (remember that 99% of pirates in OP are actually terrible people). So it’s understandable if Fuji makes the conclusion that trying to fix the WG from the inside is better than outright overthrowing them and inviting anarchy.