It's not confirmed to be connected to germa
And personally sanji is more likable as a person, I don't care that much about fighting, and sanji being naturally strong also adds depth to his character, like the cosette scene or all his moments with usopp, he is a kind-hearted dude who wants to make others happy despite him being arguably better, he still considers everyone else as more worth it, sure he's a dumb simp sometimes but that doesn't remove the fact that sanji is a kind a guy and the moments where he seems completely powerless like in WCI show what kind of guy he is, "I know I can't stop the assassination by myself, and I have nothing but hate towards my family, but I want to save their life" that line hits hard