For the uninformed: https://mangarock.com/manga/mrs-serie-183717/chapter/mrs-chapter-183930 page 21
I agree with you btw, the gag of Sanji being a pervert is funny especially because it's so absurd. Sometimes I think people just say they hate his perverted actions because they think they are supposed to say that?
That sounds a whole lot like the concept of "virtue signaling", which is commonly used to dismiss the opinions of progressive people - according to virtue signaling people calling foul on stuff like Sanjis pervyness don't really mean what they say, but are just saying it in order to uh, get internet points, which I guess can be exchanged for something or other. Anyway, If one calls out "Virtue Signaling!" in order to skip over the substance of others criticism entirely in order to defend something because it must be defended by default, one is just providing a shallow knee-jerk "virtue signal" of their own.
The fact that he does something that is obviously not ok makes the joke funny. But hey, if people wanna make a fuss about an obvious joke, I won't stand in their way.
"Its a joke" can never absolve something of criticism. How the joke is told, in what context and what it implies also matters.
For instance, even if Sanjis perviness is presented as exaggeratedly goofy, it takes place within a series that has near-universally agreed upon issues with its portrayal of women, and where said women are almost always drawn with the male gaze in mind and used for fanservice. Sometimes Sanjis pervyness can even set up fanservice, such as when it allows Nami to grope her boobs in the freezing Punk Hazard wasteland, and with chapters like this Oda is inviting us to gawk at the subject of Sanjis desire, essentially assuming we're just as pervy as him. Its hard to write him off as "he's supposed to be a comedecially huge creep in the readers eyes!" when that is the case.