I've always hated level scaling too. It makes the world feel fake and breaks immersion imo.
Games could have progression and differing levels of challenge without scaling anything, and you could make that progression apparent through NPC interactions and the scenery of places.
Starter areas might be parts of a city and the surrounding countryside. Your early challenges might be petty thieves (with missions to collect stolen items or catch a pickpocket), hunting animals (deer, wolves, some fantasy creatures that don't look too threatening), and the like. NPCs in the city could comment on dangerous creatures spotted in certain places, giving the player an idea of where he might find a challenge when he wants it. Like rumors of an orc encampment, drake lair, rampaging bear, or even advanced threats within the city like a job to hunt down a skilled assassin or band of robbers. Other areas could be a mystery, but the difficulty level could be hinted at by what the place looks like. Corpses of creatures that the player has encountered before and knows the strength of could be used to show a strong predator is in the area. See a big pile of bones outside a cave, including some that you can recognize as the bones of a dire bear? Yeah, that cave is probably home to something a lot more dangerous than the bear. A dark and spooky looking forest with webs on the trees might cue you in that this is that nasty forest full of giant spiders and dangerous things that you heard about in the city's tavern.
For powerful humanoid opponents you could have banners and signs and things that the player can learn to recognize. Approaching a fort, you see a banner flying for the Red River Bandits - and you know from seeing the wanted posters around town with high bounties that these are some serious criminals. Other camps might have the same banner, alerting you to either stay away or go there if you've managed to take them down before. Or even other things that would be recognizeable as certain groups - skulls on poles, graffiti, etc. You could even design "safe" ways for people to learn about these groups without having to go in and die - maybe you witness a battle between city guards and these bandits, and the bandits almost win - you've seen the guards in action before against weaker critters, so if the guards are dieing you know these guys are a threat you need to avoid until you're tougher.
People would still die if they ran off oblivious to the piles of smoking dead adventurers and mammoth bones and rushed into a dragon lair, but they should die for being that dumb. If a player can just rush in anywhere and be fine, the game has just lost all sense of challenge and most of its entertainment value. Even if the player has to die a few times to figure out his boundaries it isn't a bad thing, it just gives him a reason to advance to the point that he can break those boundaries. And forcing the player to run screaming for their life after biting off more than they can chew isn't a bad thing either - as long as it isn't one of those annoying forced retreat encounters some game designers program in with plot armored enemies.