Allow me to explain why Oblivion is better than Morrowind.
Morrowind was bland. They gave you all these character customization options and they were all pointless, because everyone made the exact same character who was master of melee, magic, bow and stealth. Much of the magic was pointless too. Ice did the same thing as lightning and there was no reason to have one over the other. There was maybe one enemy weak to lightning and one to ice, and you rarely ran into one of them. Starting out in the game combat was terrible. You couldn't hit anything until you swung at them 20 times and you constantly got your butt handed to you by crabs and rats. The environment was ugly, there was mud and ash everywhere. You could level up very quickly in Morrowind by running, jumping, and bartering, and once you got to level 20, the game suddenly became a stroll in the park. There is such a big world to explore in Morrowind and after you explored just a tiny part of it and leveled up a little, the rest of the world suddenly wasn't a challenge. There also was certainly no more plot in Morrowind than there was in Oblivion. If anything, there was less.
Oblivion is great. Right from the start you are fighting off Goblins and any rats you come across die in one hit. You don't have to worry about missing swing after swing like you did in Morrowind. Every swing hit its target unless they had their shield up blocking. The whole leveling system was better too. Enemies leveling up with you created a difficulty scale that Morrowind never had. If you got your butt handed to you by a scamp or some other beginner monster, it was because you tried to exploit the leveling system like you could in Morrowind, by developing non-combat skills. This makes sense, if you don't train your combat skills, your enemies will surpass you. And character customization finally mattered in an Elder Scrolls game. If you wanted to make a character who fought mainly with melee, you could master all the melee skills and max your level out at 30. Same with magic. Or you could master both, but that would require a lot of planning and you would have to max your level out around 50. The problem with this is the enemies would become stronger if you maxed your level out later rather than sooner. This meant if you wanted to make a barbarian who only used melee and maxed his level at 30, you would be more effective at melee than a character who used both melee and magic and maxed their level at 50. This makes sense, because why would a person who uses magic and melee be just as effective at melee as someone who only focuses on melee? They wouldn't, but in Morrowind they were and in Oblivion they aren't.
And it sounds like some people only prefer Morrowind, because of nostalgia. It was probably their first open world game. Yeah, Oblivion had a limited selection of voice actors, which was new in a world with this kind of scales, but that is so obviously not what they focused on. There is an entire world to explore and immerse in. Voice acting should only be an after thought.
Morrowind was bland. They gave you all these character customization options and they were all pointless, because everyone made the exact same character who was master of melee, magic, bow and stealth. Much of the magic was pointless too. Ice did the same thing as lightning and there was no reason to have one over the other. There was maybe one enemy weak to lightning and one to ice, and you rarely ran into one of them. Starting out in the game combat was terrible. You couldn't hit anything until you swung at them 20 times and you constantly got your butt handed to you by crabs and rats. The environment was ugly, there was mud and ash everywhere. You could level up very quickly in Morrowind by running, jumping, and bartering, and once you got to level 20, the game suddenly became a stroll in the park. There is such a big world to explore in Morrowind and after you explored just a tiny part of it and leveled up a little, the rest of the world suddenly wasn't a challenge. There also was certainly no more plot in Morrowind than there was in Oblivion. If anything, there was less.
Oblivion is great. Right from the start you are fighting off Goblins and any rats you come across die in one hit. You don't have to worry about missing swing after swing like you did in Morrowind. Every swing hit its target unless they had their shield up blocking. The whole leveling system was better too. Enemies leveling up with you created a difficulty scale that Morrowind never had. If you got your butt handed to you by a scamp or some other beginner monster, it was because you tried to exploit the leveling system like you could in Morrowind, by developing non-combat skills. This makes sense, if you don't train your combat skills, your enemies will surpass you. And character customization finally mattered in an Elder Scrolls game. If you wanted to make a character who fought mainly with melee, you could master all the melee skills and max your level out at 30. Same with magic. Or you could master both, but that would require a lot of planning and you would have to max your level out around 50. The problem with this is the enemies would become stronger if you maxed your level out later rather than sooner. This meant if you wanted to make a barbarian who only used melee and maxed his level at 30, you would be more effective at melee than a character who used both melee and magic and maxed their level at 50. This makes sense, because why would a person who uses magic and melee be just as effective at melee as someone who only focuses on melee? They wouldn't, but in Morrowind they were and in Oblivion they aren't.
And it sounds like some people only prefer Morrowind, because of nostalgia. It was probably their first open world game. Yeah, Oblivion had a limited selection of voice actors, which was new in a world with this kind of scales, but that is so obviously not what they focused on. There is an entire world to explore and immerse in. Voice acting should only be an after thought.