Mel Brooks has himself stated that a film such as Blazing Saddles could not be made today.
Because it wouldn't be interesting. Back then racism vs blacks was so normalised that hardly anybody reacted when people said racist things. Brooks just took that everyday racism is put it on screen in a context where it's laid clear what's happening. And then it became funny. In that context it was an anti-racist film. But we don't have that society any longer. So if it would be made today it would just come across as a racist film. When we watch it today we react positively because we know the context and accept it.
If you wanted to remake Blazing Saddles today and find the same note, you'd need to remake it to be about Muslim Arabs. But even so, racism against them isn't quite as overt as anti-black racism of 60'ies USA. So I'm not sure it would fly. Not to mention our cultures media savviness and their meta-meta-meta-meta humour. It's harder to write today.
It's not a question of not offending. It's about making it funny. Funny is funny. If it isn't funny it doesn't matter how clever or pc something is. Also... Blazing Saddles was written by Richard Prior when Prior was at his funniest. It's debatable whether we've seen a comedic genius of that stature since. The thing with funny is that you get away with being edgy as fuck. Edgy humour that falls flat is usually just horrendously offensive. Blazing Saddles walks a razors edge and nails it all the time. That's amazing writing. It's hard.