Ubu

Wondering if anyone can advise on the merits of laying new wooden flooring over existing floorboards vs just replacing the original floorboards. Moved into a house where the upstairs rooms all have the original floorboards exposed. I think they are beyond restoring as they're uneven and quite badly damaged. I don't know whether it's best to install new wood floors over them or take them out altogether and start again with new ones. Grateful for any advice.