My apologies if there's an FAQ on this I didn't find. Redirect me if appropriate. I haven't been carrying a jack and tools to change a tire if necessary; in general, I have road service for that. ...
I agree that it is wise to carry what is needed to change a tire including the spare tire itself. This way whatever help you get, it can get done.
I suppose if you are the kind of RVer that travels the main roads from one big RV park to another, you might feel differently. But for those who like to get off the beaten path, carrying all you need makes sense. If you are carrying a spare tire, you are already carrying the worst of it.