Lois and Jimmy could've just explained, you can do good, just not too much good, see?

Another one from just before the Byrne-era reboot, that maybe underlines why that was needed: from 1986, Superman #418, "The Replacement!" Written by Cary Bates, pencils by Curt Swan, inks by Dave Hunt. Cover by Eduardo Barreto.

Mid-change from Clark Kent, Superman is abducted by aliens, but with good intentions: Superboy had saved their planet long ago, and it was now under attack by a "cloud-eater" they couldn't defend against. (Although advanced, the aliens were silicon instead of carbon-based, and the cloud-eater would gobble them up!) They beg to teleport Superman across the galaxy to save their world, and Supes of course agrees. The aliens apparently only had enough juice to teleport him, and get ready for a long flight back, but first leave a thank-you for Superman: a temporary replacement, to take care of earth while he was gone! One alien wonders if maybe they should've mentioned this to him; the other is like nah, it'll be fine.

The replacement makes himself known quickly, stifling a bank robbery by flattening the getaway car, then repairing instantly his damaged arm after a bazooka hit. Lois is on the scene to get the story, but worries about what this means...and where it might be going. Sure enough, the next day, Metropolis is disarmed, as every gun in the city is turned to dust. Although there's no proof directly tying that to the new "Superman X," Lana Lang reports "speculation runs high," but the replacement does score some points by quickly stopping a mid-air hijacking by Metallo. This seems to inspire another feat, as all the Kryptonite in Metropolis is turned into sandstone: yes, I think that'd been done before, but more had turned up since then? Krypton was a big planet and most of it apparently landed here...

Superman X then starts healing people at the local hospital, preventing car accidents with force-shields, and maybe funnest of all, powers-up Metropolis's senior citizens so they can protect themselves! The effect looks like Granny has learned to focus all of her chi into her iron fist. Then, he sets up broadcast towers, for a radiation that while harmless, forces criminals to turn themselves and their misbegotten gains in; and Lois and Jimmy decide yeah, things have gone too far. Using Jimmy's signal watch, they call in the replacement, for a prepared lecture on Superman's need for restraint. Maybe a PowerPoint. They also had news footage from Lana, of a bad scene at the hospital, which was mobbed by out-of-towners trying to get in on Superman X's cures, and a boy was crushed in the riot. Although he had been silent up until then, Superman X wails in anguish, then takes off into space, presumably headed home; while Jimmy ejects the video--which was fake! They made up the dead kid, to try and teach a lesson; figuring the replacement would have shared the real Superman's code against killing or unnecessary death. That strikes me as too far: if you have to lie to make your case, how strong is it? Or, was that the only way to de-escalate events before somebody really got hurt?

Everything returns to normal, or at least so they say: were the guns and Kryptonite all restored? The sick that had been cured were still good, anyway; so some good had come of it; but as Superman returns with a story for Lois and Jimmy, this time they had one for him.

There were more than a few stories like this, back pre-Crisis; trying to explain why Superman hadn't wiped crime or disease or weapons from the face of the earth. I think there's one with the Guardians of the Universe, where they accuse Supes of making earthlings soft and dependent on him? Post-Crisis they were largely able to say "Superman is mortal and fallible, not God" and call it a day.