Why the Independence-class light carriers resisted modernization

How could the Independence-class light carriers have been modernized?

They were too constrained by their cruiser-conversion origins; rebuilding them deeply would cost more than constructing a better new carrier.

The class was a wartime expedient built around hulls and materials already available. That origin produced useful flight decks quickly, but it also embedded compromises in space, structure, and arrangement. A serious modernization would require stripping away so much of the existing ship that the conversion's original economy disappears. The class could therefore be a successful emergency asset without being a sound long-term carrier design.