Would Russia have recovered them if Ukraine did not want to relinquish them? Maybe, but in the 1990s they were in very bad shape, and before 2004 (and between 2010 and 2014) Ukraine was under a pro-Russian government.

The point here is that, at this point, if any country is under the illusion that it does not need nuclear weapons to maintain its independent existence, they probably deserve to be absorbed by their neighbors.

And Russia didn't want them to have them and knew their exact locations.

And NATO and the rest of the world saw Ukraine as a violation of the non-proliferation treaty and didn't want them to have them.