Even Skyrim wasn't bad. I put like a thousand hours into it. It's just not exactly what I'd call "ultimate".
Oblivion was good. It's dated at this point and like Morrowind combat is not comparable to say Elden Ring. Oblivion solves the whole open world (as in OpenCities) thing in mods, but Morrowind has it to start with. Which is why I think Morrowind is the closest the series has been to my ideal.
Also ES has some of the best, deep, insane lore. The series is at its worst when it tries to be grounded.
Even Skyrim ends with you going to the afterlife to gather aid from the dead and fight the embodiment of the cyclical nature of time by imposing the concept of mortality on it. And somehow that was a bog standard dragon fight.
Unless they've made some major engine changes... I feel like it's going to be hard to top games like BG3, Elden Ring, or even Breath of the Wild.
BG3 has the deep story and npcs. Elden Ring has the emphasis on combat. Breath of the Wild freeform exploration.
Yes, I want a game that combines all of those and in the ES series the closest was probably Morrowind (combat being perhaps the most notable lack.)
I don't mind the fishing mini game in Breath of Fire 3. You can see all the fish and it's just a matter of skill not patience. That said, it's optional (the only fish you need, I believe you can buy) and trying to 100% it is a chore I'd rather not do again.
It's not super painful in Soulsborne games but it's still enough of an annoyance they got rid of it in Elden Ring.
I think it's fun to work down a questline for an NPC, but I agree that attempts to make it more that a simple branching dialogue tend to fall a bit flat. I also tend not to like the gift giving grind a lot of games do. I much prefer to go do things with an NPC and often that forms a better bond than an NPC with more dynamic dialogue.
Rather than saying it's better than say Oblivion, I'm saying it's closest (among the ES games) to being what I'd want out of an "ultimate" ES game. Oblivion has mods that fix its bixest shortcoming (OpenCities and various magic mods) but I'm not inclined to give Bethesda credit for the work of modders.