Only in special instances. And those don't happen very often.
I don't think most clients really want to screw around processing files.
But for the sake of argument, lets go back in time.
I used to shoot 4x5 chrome by the case load. I had it processed, picked the brackets and delivered it.
The agency had it scanned and retouched as needed ( not). One could argue they got the "raws"
As a general rule I was mostly happy with this workflow. Once in a blue moon something I wanted fixed in post did not get done. Still we made a lot of images and a lot of money.
Now I shoot with post processing in mind, which allows me to do things that were near impossible with 4x5 chrome. Not on every shot of course but quite a few. And I can fix things to my satisfaction before the files leave.
When i have been asked for raws, that's the argument I put forth.
But somedays after staring at the monitor for way too long, delivering a box full of chromes seems like a really good idea