Our experience has been “more conveniences, the less room”. There are some exceptions of course. Also, some older parks with electric and water but they are often a bit tight for bigger rigs.
A lot depends on where you are and when you are traveling. Currently we are traveling through North Dakotas and in some portions, camp space is at a premium because of the oil boom. Those camps we selected were State Parks with either no hookups or electric only.
Then we are in “camp and go mode” where we do not unhitch it make very little difference what the campground is like.
The Good Sam campground finder is an excellent place to start. A few phone calls and web searches usually produces what we want.