The simple answer is "It depends." Covers can be foam soft to "bone" hard (fiber-epoxy laminates used in highly loaded paper calendering rollers) to no cover at all.
More than anything else, process lineal nip load (N/m or PLI) and peak pressure under the nip (Mpa or psi) determine what cover options will survive. Here, a laminator nip may be 10-100X the load of a winder nip and a calender nip can be 10X higher still. So, you need to know your process application well to make the first cull of cover options that can survive.
The second cull will be for any cover temperature and chemistry limitations. Once you have the shorter list of cover hardnesses and chemistries, the answer may become simpler. The softest cover (that still does the process work) that you can afford to maintain in good condition. That is because the softer cover provides more ‘forgiveness’ to variations in web, cover and roller. Thus, for many applications it is simply a tradeoff between life (ongoing costs) and quality (uniformity of nip).
More info: https://www.youtube.com/watch?v=_R2Iidv33Y8