If you can be bothered to use 2 thirds of the time on a chop just looking for the right donors, a full on c+p job can easily be creative, but you need inspiration to be creative. Realism for me is mostly about photorealism, because I don't really see any limits as to what is possible/impossible when it comes to car modifications.
But if you are going for extreme mods it's silly to try to hide it (like just using a different base and end up with a full on invisible bodyswap)
I have no problem with someone cutting the front end off a Merc and pasting it on a BMW, if they make it look like someone actually did that irl. I like everything that is well done and looks good tbh. But it can still end up being boring if it has nothing more than what is already available in pictures already, so prefer trying to do stuff that has not been done before.