After ignoring the TES games my whole life, I first played Oblivion a few years ago, and for once in a very long time, I felt the same feeling I did when playing GTA San Andreas for the first time as a little kid.
I spent the first 10hrs or so just stealing stuff and fighting in the Arena, didn’t even touch the main story. In Oblivion, there is soooo much stuff to do, and I didn’t even mod it.
Elden Ring is definitely a great game, but it’s pale in comparison to Oblivion when it comes to “freedom to do anything”. Even Skyrim couldn’t top that for me. Don’t know about Witcher 3 though, I have yet to play it.