You're talking about other qualities. Reactivity. Challenge. It's important, of course, but the genre as a whole has huge problems with those things. As
aweigh can testify you can only get a challenge in those RPGs that hardly have any roleplaying, like dungeon crawlers a la Wizardry, to win there you have to play a role of a desperate tactician drawing maps and calculating optimal builds. And reactivity you mostly get in immersive sims a la Deus Ex/Dishonored or roleplaying strategy games like Crusader Kings or - very rarely - systemic RPGs like Din's Curse or Space Rangers or even Sid Meier's Pirates! If you compare reactivity and challenge of Skyrim to, say, Planescape (or whatever good RPG you have in mind) then the difference is in the density of rails and branches in the world. It's pretty clear that as a game itself Skyrim has more reactivity than Planescape, but the game itself is much bigger and huge portion of it is dungeon crawling lacking any roleplaying choices or reaction to your behavior.
In first, say, 5 hours of Planescape you have maybe 20 quests available to you, 15 of them can be completed in 2 or 3 ways, but, say, only 2 of them are not self-contained and affect anything beyond those specific quests. Plus everything affects your morality score but it's hardly ever a good system, even Dragon Age companion relations is better and more nuanced, I'd say. In Skyrim you'll have access to most of the game content in first 5 hours minus level-locked quests and long questlines. It will be something like 100 quests maybe. Pretty sure that 20 of them will have varied ending giving you roleplaying options, and due to systemic nature of the game maybe half of those quests will have reprecussions for the whole game unlocking companions, spouses, friends in cities giving access to thane quest and so on and so on.
But beyond those quests - traditional RPG won't give you a lot of roleplaying choices outside of clearly defined crossroads. Most of players back in the day considered freedom to be an ability to kill any NPC and see if the world would react. Meanwhile in Skyrim many actions like stealing have repercussions: dudes are hired to beat you, friends can give you gifts, vampires kill your friend and you get inheritance and so on and so on. There are no big branching narratives but I'm sure you can see how those little things may be even more immersive compared to traditional RPG. That traditional RPG will never be able to give you enough freedom or react to all possible outcomes but Skyrim can amaze players by people telling them to stop fucking around when they jump on the table. FFXV clearly took that approach with a lot of reactions to little things and dozens of small self-contained quests with limited choices.