First of all, I don't want this show to end. The last seasons weren't as good as the previous ones, but some episodes still makes me laugh. I hate "political correctness" but I don't think this is the only thing to blame. The show still have some dark jokes, most of them aren't funny or just feel out of place.
Family guy was never about just offending people and things like that. Of course the show had real dark humour, but the cutaways were always fun, the core of the characters were always nice (evil baby stewie, sex maniac quagmire, and the list goes on..). You can't see any of that nowadays. The cutaways aren't funny, the characters act randomly. Its just sad.
Most of the jokes talk about Hollywood celebrities/people I have never heard about. Writers must get out of their own bubble and write things for common people to have audience. Their internal jokes about people only they and some friends know is just a bad idea.
I always get excited to see new family guy episodes, but when I watched this episode I got my phone before the first 10 minutes. I've watched a lot of episodes that aren't the most funny ones, but they still keep me hooked for the whole thing: story, characters...
You can breakdown the whole thing and see that it doesn't make much sense: for example, the first part Lois talking with Stewie about cookies and his mini dinner - it wasn't funny, it didn't contribute to the story. So what was the point? Other example, Stewie telling Brian "avoid India" and Brian answers "Really?" and then goes to another scene? What the.... Looks like people producing it are just lazy "ok we have to fill 20 minutes and we got nothing else, just throw something there and it's done".
Long story short: it can still be saved. Just people who love the thing to produce/write.