Really depends on the specific needs and how many you'd have to accommodate. On Saturdays, a friend hosts a biweekly dinner, and he's complained before that it's difficult in winter to accommodate different preferences. (One is gluten free, another hates soups, and I don't like spicy food.) Personally, I feel like the hardest part of that mix is the gluten free aspect, and not even that hard... there are tons of non-soup meals that aren't spicy. (I know because I eat them.

)
But I have another friend who is allergic to eggs, dairy, and nuts, and doesn't eat meat, and I just try to mimic foods I've seen her safely eat, because a lot of packages will say they "may have been made in a facility that also processes [something that will kill her]."
And I have a friend's kid who is deathly allergic to garlic, beef, and Yellow No. 5, and my friend always tells people to not worry about trying to accommodate her. People have tried before, but scouring ingredients lists for Yellow No. 5 is not a thing that occurs to most people, so she's better off just taking care of her own meals.