You can fail some quests in Skyrim.
I'm curious about some examples, because I just remember the first Thief quest, where the outcome doesn't matter, he'll still welcome you in the guild (though I've not tested them all to see which are failable or not).
NPC reactions and their attitudes towards you might not have a +15 to fire damage effect, but that doesn't mean they make no difference. They don't have to have material inventory benefit / penalty to affect the world. RP'ing is helped by the choice to be a complete arse to a person and make them glare at you for the rest of the game, or choosing a side in a war (so you can RP political allegiances, patriotism, etc). It might not move mountains, but hey, it helps you RP.
There's no relationships between NPCs. Helping someone won't make me friend with his friend. Helping his enemy won't make me his enemy. Being a stormcloak won't make me at least a little bit hostile with Empire supporters.
If I steal someone, get caught, there'll be no consequence with that person. He'll be as friendly as ever.
If I help people, I'll not be particularly known as a do-gooder, no more that I'll be known as a bandit if I raid a hold and then go to another one. Imperial guards could despise me if I'm known as a thief, companions could think I'm a feeble mage if I'm part of the College (but maybe still accepting me if I prove myself). That's what helps RP way more.
I'm a fervent Empire supporter and I helped them a lot ? Others Empire supporters will be my friend, get me discount if I go shop to them, tell me their secrets, give me quests, and so on. When I defend Whiterun, people would like me after that, I protected their home. But when conquering Winterhelm, people would still be hostile, I defeated their leader, and attacked their town. On the other hand, Stormcloack supporters would hate me, refuse to trade with me, don't give me quest, etc.
You don't have to get in every guild at once, you can wipe at least one of them out. You don't have to do a quest just because some random NPC asks you to.
In Skyrim, I can be both an Imperial guard, and help the old woman to free his son from Imperials. The quest doesn't give me any other choice. I can't tell her that her son was rightfully imprisonned or that he was a traitor. I can't tell her that he died (lie).
There's so many times where your character can't say no. It's just "Not for now, but repeat me that everytime I asks you".
The worst part is that the main quest where I have to become part of the Thief guild. My character isn't a thief, but because I have to for the sake of saving the world, he'll get in the guild. I wish there was an option to tell "No thanks, I'm not a thief, however, how about you give me that information against x gold, or that I do something else ?" The game is litteraly forcing my character to try to be a thief and get in the guild.
You can specialize in magic/sneaking/beefiness if you so chose, or cross-train. That is, in fact, more choice than being a mage and thus unable to heft anything more than 5 pounds, no matter your actual physique.
There's a difference between being able to specialize in a few skills or being medium to lots of skill and just do perfectly everything in every category. For example, in Morrowind, I could be a mage with heavy armor, but in that case, maybe there's some magic skill I wouldn't know much about. Or maybe a warrior that knew how to lockpick, but barely to repair his armor.
And the weight system is nearly the same, but with stamina instead of force/endurance.
By the logic you've presented, sure you can chose a few lines of dialogue in other games, but all that does is play a different .bik file for the ending cutscene. Sure you can hire different RPC's, but all that does is alter the stats of your party. "Aesthetic" things, like everyone in town talking to you differently and the ruler being a different person with a different face and a different voice and a different attitude, seem like a big deal to me. All the guards wearing different uniforms is a lot more than you'd get from most games.
So be it. You prefer eye candy, while I prefer consequences for a RPG.