Alright firstly... let's not act like modern day Superman is some weak chump here... all the strength and durability feats that have been cited so far pertain to modern Superman, not pre-crisis. Modern Superman is still way, way too much for Goku to handle. I'm also not sure why you're basing all his abilities on a comic that came out in 1992, as though there's been nothing since to suggest Superman can outperform that... I guess it's probably because that's the only Superman comic that a DBZ diehard has any interest in... plus, in any situation where Superman fights an enemy in a populated area, the "World of Cardboard" speech applies. If a human is in range to see the fight, then the fight probably doesn't demonstrate Superman's top end.
Ah that's some copout; it's not like in the previous example of fighting all the way around the world the world is depopulated.
Ok so you are going to discount doomsday because of random reasons. Let's rise up to COIE, where at some places there are no such excuses.
I'm not saying DBZ characters can't take powerful punches... but powerful by what metric exactly? By the metric of characters squatting some hundreds of tons in 10X gravity... or powerful as in bench pressing the weight of the earth effortlessly?
I feel that the bench pressing example doesn't translate to punching power; normally it would be related, but again, you are the one arguing that regular physics don't apply here. Superman's fights don't show bench pressing planet strength, or else the planet itself would collapse when someone takes a punch and is not sent flying. That's not what we see happening in any for reals battle.
As far as I know, there's no example of a DBZ character taking a hit from someone with Superman's strength, which is exponentially greater than someone like Goku. I'm also not sure what's convincing you that Goku could dodge it either considering how much faster Superman is shown to move than anyone in DBZ. Goku probably couldn't react to Superman flying at him at top speed, let alone a punch as fast as Supes can throw it.
Again, why doesn't he do that stuff against Doomsday. Or Darkseid. I don't doubt he can do it, I doubt it'd work in a fight, particularly a fight against someone who is used to fighting stronger enemies (unlike, say, Darkseid).
It would have applied even prior to the existence of DCAU. It's inherent to Superman's character that he'll try and keep the people of Earth safe at his own expense. In a SA style Death Battle though, that concern would be removed.
At some points Superman does fight Darkseid on Apokolips. Surely those kind of limiters would be removed there. Or for example, in COIE when fighting the anti monitor. At some point Supes, in space, with no civilians around, with literally
everything on the line, goes all out against the Anti Monitor, and he does almost nothing. Supergirl does
exactly what you suggest. It does damage the antimonitor's body a little enough to force him to retreat, but we don't really see the world they are on damaged more than what's caused by the antimonitor's body falling.
Now, that world does weak them, but only a little. They are still super strong, super fast. The only thing we see that makes them weaker is that they can bleed. As far as we see, it is the only effect. The world is harsher, but Supergirl has no trouble picking blocks and chucking them. They are still super powerful.
So again, why, with no civilians around, with literally the existance of everything on the line, why their fight doesn't destroy
at least the world they are standing on. When the super people actually pull out the very stunts you suggest, there's little colateral damage.
The answer is, they are trying to hit hard, but are not hitting really hard by any measure.
Meanwhile, when Goku and co fight, shit explodes around them. Planets literally explode under their feet. Or they have to deflect attacks to protect the planet.
They actually fly at super speeds face on against enemies. All that ends up happening is some columns fall. Now, the fortress does destroy itself after the battle, but it seems to be the antimonitor just doing it out of spite. During the battle itself, there's little damage.
You may wax theories about super strength from benching planets, but in coie, when it actually mattered, they weren't really hitting that hard as the so called planet benching would suggest. And if they didn't pull it out in COIE is because they just can't, because at several points there's no way to hold back. There are no higher-than-COIE stakes. No "death battle rules" to suggest they can perform better than that if they really wanted to. No civilians around excuses blah blah.
What we really see is that they are not that strong. Flying fast against an enemy doesn't work that well.