The word can have swearing but not genderisation which might be offensive (mother) nor allusions to sexual dominance (motherfucker). Nor, other possibly offensive connotations. It seems that the word is commonplace and people won’t stop using it, so an alternative to the word may be useful. But the problem with alternatives, is that people might not use them unless they carry a meaning that’s attention grabbing in some way, and when it comes to this word it needs to be able to be used in either a serious (non-funny) or comedic way.
Jawn and motherfucker are probably the only 2 words I could consider to be general purpose nouns that can be used to refer to pretty much any person place or thing.
I feel like in the case of MF though, vulgarity is kind of the point, it’s meant to be insulting, whether seriously or playfully. Jawn doesn’t really have that same negative connotation, so it sort of falls short on that count.
And of course motherfucker has added utility as an adjective by swapping in the -ing suffix. You can have a motherfucking jawn, but you wouldn’t normally have a jawning motherfucker.