Exactly, there was no difficulty curve because everything leveled with you. While I would prefer a completely unleveled world I think the FO3 system is still miles ahead of Oblivion's system (which was, to me at least, one of the worst gameplay mechanics I have ever seen in a game).
I remember when I first played Oblivion without knowing anything about the inner workings of the game. My character had athletics, alchemy and probably some other non-combat skills as majors and I mainly leveled up due to these skills. I entered the Kvatch gate at around level 10 for the first time. It was quite hard and I ran out of health potions before I even reached the Sigil tower, so I decided to level up a bit and find some better gear. When I came back at level 15 (including better gear) it was impossible. That was the point where I found out something was terribly wrong with the game. Without mods I probably wouldn't even know that Skyrim was announced because I would have lost interest in ES games.
This is exactly correct. It wasn't just that enemies became more powerful as you leveled, it was that, for a time, they became more difficult for your character to kill than their counterparts had been when you were at a lower level. Levels 10 through 18 were probably the most difficult and dangerous time for your character to exist in the world. Too strong to run into many weak enemies, too weak to really pawn the stronger ones. And maybe there was some sense in that, but it soon ran off the rails and got carried away.
And it hurt the game experience. It not only made your character seem less powerful and unique once they had attained a certain level, but it also made powerful enemies seem less special and unique as well. When EVERY dungeon you enter is completely teeming with some of the most powerful enemies in the game
( half-a dozen goblin warlords in every goblin cave you come across, or half- a dozen gloom wraiths and liches in lurking in EVERY other room of EVERY dungeon, Daedric Forts where the Valkynaz [Dremora Princes] and Xivalai outnumber the Kynmarchers[Dremora sherieffs and field seargents] by seven to one). . . it makes game play tedious, and completely steals away the intimidation and awe that the games more powerful denizens are supposed to command.
Constantly scaling up everything damages plausibility.Its like if in Lord of THe Rings, Gandalf The Gray returned in his more powerful incarnation. . . and in order to balance it, Saruman sends, instead of uber-orcs, and army of Balrogs to assail Helm's Deep, or if Luke masters his Jedi skills, only to find that the Death Star is manned ENTIRELY by an army of hundreds of well trained Sith Lords. For one thing, it tends to defy logic. How in the hell would Saruman have gotten a hold to an army of ancient Demon Lieutenants? Also it marginalizes the advancement of the heroes and the granduer of their enemies. What would the point of Luke mastering The Force have been if the end result was that every enemy he encountered would also have become a master of The Force? And if every soilder in every enemy force is a Captain among Ancient Demons or an evil master of The Force, then what is so special about a Balrog or Darth Vader, anyway?
And that ties in to what the OP said about how at level 20 it took the guards a long time to do him in. In a phrase, after level 20, its supposed to. The 20th level doesn't mean the same thing in gaming circles that it used to, but there was a time, in the ancient days of Dungeons and Dragons and game boards with multiple players campaigning as a party of heroes in an old school RPG game, when Level 20 was a big f******** deal. Lesser mages, for example, could only cast spells so many times before they would have to memorize them again, but at level 20 you could cast lightning bolts out of your fingers, your butt and your eyes all day long without a backwards glance. 20 was where you went from being a hero to being a virtual demigod. To reach the 20th level was to shatter through the glass ceilling between heroic and Legendary. And legendary meant you were smarter than the average bear, and tougher than the average goblin warlord.