Ok, perhaps I went too far. I just think Nolan's way of getting at the human issues you describe is far more successful than burtons.
Overall, he has. I'm not doubting that. But human issues have nothing to do with a setting in fantasy or realism. It transcends genres because it's universal.
Great film according to most people. Your typical fantasy/sci-fi big action movie that still holds up very well today. A lot of people would consider it one of the best of it's kind. Now this movie to me has mass appeal because it's a sci fi story. Fantasy yes, but it makes you feel like this could happen in the real world (in the context of watching the film). There is a real connection with nature, and prehistoric creatures inside a fantasy amusement park set up. It works because it's a great script and great direction that pulls at the human elements which most films fail to attain. Is it the big fantasy narrative that makes it successful or is it the taking of these fantasy creatures and putting them in a real world context that made it a classic blockbuster? I guess it just all worked well together. My point is, fantasy movies can be very successful but they usually focus on bringing fantasy to real life surroundings.
Fantasy in and of itself has mass appeal because it's escapism at it's finest. It has no real limit, and frankly offers whatever real-life cannot provide. As you noted, one method is to bring fantasy to the real-life. And yes, that works. Jurassic Park is a great example of utilizing plausible circumstances to the application of a fantasy narrative. There is no doubt that works.
But there's also the other side to that coin, which is bringing the realism
to the fantasy. It's what I spoke of earlier in that at it's core, the most successful stories use "real" emotion. The Star Wars and LOTR trilogies are prime examples of what I mean. They may take place in a made-up world that's littered with monsters, magical forces, etc...but under all of that glam are character arcs and socially relevant issues that are none too removed from our own. Yes, the Ring is an awesome and totally unreal object. So is the lightsaber. But that's not what makes these stories so adored by fans. Luke's journey and his relationship with his father, mentor, and sibling, are ultimately where we connect with most. Ditto for Frodo with his best friend and conflict wielding such high resposibility. THAT is what makes it real. And ultimately, why "fantasy" doesn't intrude on the structure and layering of a story.
I shouldn't have been as black and white in my assessment. The way I look at the burton films, they don't have that much of a different approach than Nolan. They are still taking a fictional character and trying to put him in the real world. You have some dark, real, gritty scenes in the first two Batmans. The difference for me is how much you stray from the comic books, and how does that affect your audience. The best example in these films for me is the scene with joker's hand coming out of the vat of chemicals.. That comes off as cartoony to me and I think it makes it less about reality and more about fantasy. I think Nolan took it further in making batman come into a "real world". Obviously, Burton's goal wasn't to create a literal transfer from comic book to film either. I just think his style is more fantasy oriented. And I think Nolan's "real" preference has more mass appeal, I also think it creates more depth to the story.
I could be wrong, maybe there is some great director in the future that can pluck these characters out of the comic book literally and still make a great movie that lasts through the ages. I doubt it though.
I point to the paragraph above. You can take as many unrealistic and fantastical elements as you want, I guarantee you there's a means of writing it in such a way that motivations and drives of a character are all real. I understand what Nolan did with Joker, and it worked out great. But that is not to say that was the only way the character could have been brought on-screen. Even to the degree of his menace or gravitas in captivating the audiences.
The elements that made Heath's character so great? STRAIGHT from the comics. Same comics where Joker is a literal freak, however unrealistic that may be. There was nothing in TDK's characterization of Joker that didn't in some form owe it's nature to the source material. The
real difference between Nolan and Burton's interpretations, is Nolan was more technically proficient in combining 70 years of history into single stories. All there is to it.
The whole fantasy vs. reality issue in this context, is quite simply incidental.