Can laminate be laid over linoleum?

We did the same back then (>10 years ago). Floorboards, two layers of linoleum or PVC, on top of that we laid click laminate. In between, we also laid some kind of green foil/fabric from a roll, I would assume that was impact sound insulation.

Below us is only the basement.

My neighbors also have floorboards, they had them exposed and planed. It looks really great. I would consider it now as well.