Skyrim is still amazing, don't get me wrong! It was just a massive disappointment because they took out a lof of crucial & fun RPG stuff that made Oblivion exciting and timeless. Skyrim was like a big stepback instead of taking Oblivion and adding -more-.
They removed the random encounters with bandit camps, highway men, patrolling guards, pilgrims. No Fighters guild. The dungeons were boring and few in number, none of the environments or settlements had a magical quality to it like Cheydinhal or Skingrad had. The voice acting was flawed: you hear the same 4 people over and over... (Gideon Emery & Jim Cummings being the mot common scripted voice tracks for NPCs). The horse gameplay & mechanics are the worst I have ever seen. Dragons can be killed in 3 hits....
The huge improvments were the combat & level up system, Khajiit/Argonian/Orc design overhaul, the blacksmithing skill.