At this point, he's just too damn powerful and unbeatable. You got to whip out kryptonite or Doomsday to stand a chance. The way he ragdolls the entire Justice League, you almost wonder why the rest of them are even needed. A fight with Wonder Woman should be tough...one headbutt and she's out like a light.
The character is unrelatable. No sense of danger with him. It's like watching a video game.
Look at Thor. You could say he's Marvel's Superman (when it comes to strength and power versatlity). But though he's incredibly strong, he's not shown to be virtually unbeatable. He can be knocked unconscious etc.
Taking Superman back to Fleischer power levels is a bit much (they've pretty much done that with Wonder Woman though, and it hasn't hurt her appeal any. She leaps, not flies). But post-crisis John Byrne level at least, where other super-powered heroes and villains can give him a real fight or beat him. And he shouldn't be anywhere near as fast as Flash.
I disagree with you here. Being unrelatable has never been a problem of Superman for me. It may be due to the fact that people think of him as a muscle guy. You compare him to Thor, but Thor is not the most clever nor subtle avenger. Superman is clever and subtle, and he has a heart.
Look at BvS (I disliked the movie but that's not the point) Superman is all powerfull and yet is beaten/broken by Lex luthor when he shows the photos of his mother!
There's always a way to make him suffer, and I've never connected this to his power level.
Just increase the stakes. It's related to that, increase the stakes. Like they do it with the Flash everywhere : he's like the god of speed but even he can be too slow sometimes or has to face a problem in 2 locations at the same time. It's because his ennemies are very specific to him and what works with him wouldn't work with Aquaman or Batman, whereas I always felt people wanted a "batmanization" of Superman's rogues.
I mean, Doomsday canhurt himphysicaally, Brainiac is able to hurt him physically and his mind, Zod too, because he's kryptonian, Doomsday too, and Luthor can destroy is heart, Parasite can suck his power, whatever level of might Superman has. Darkseid too, can affect both his mind, and his heart. Same with the Eradicator.
I mean, in MoS, Superman exerts himself quite a lot.
I don't want to see him vunerable to conventionnal threats. What's interesting is to find/make drama with a "god". This is the cool thing. If Superman is down by conventionnal threats, he lose his appeal to me because he'll end up as a Thor or a Hulk. Superman smaches. " Supes Smash! " Superman is bigger than that.
Superman greatest power comes from his heart, and I have always been able to connect to him through that, I don't need him to be weaken down.