I'm sure he had no desire for such a fight.
Presumably he hoped Isildur could be talked out of it at some point later.
The real reason, of course, that Elrond did not take the ring from Isildur, is that Tolkien didn't want him to. He wanted to write a longer story.
But throwing that aside, as we can ;~D, I have speculated about the how the fact that Elrond was a ring bearer, the keeper of one of the three elven rings, would impact his ability to take and destroy the One.
On the surface, it would give him power. What kind of power, I am not sure of. I can look that up if others don't know.
But would it also make him unable to act against the One? - or the wielder of it? Tolkien didn't broadcast the fact that Elrond and Gandalf both bore those rings, but what would be your instinct be on how it would change the confrontation between the two?