Hurricanes cause more damage today because there is more to damage. Ronald Bailey writes:
[An article] in the Bulletin of the American Meteorological Association, found that "since 1900 neither observed [continental United States] landfalling hurricane frequency nor intensity shows significant trends." Hurricanes hitting the U.S. may be getting wetter and slower, but their winds are not stronger and they are not more frequent. That said, in May the World Meteorological Organization comprehensively reviewed the scientific literature and concludedthat "it is likely that greenhouse warming will cause hurricanes in the coming century to be more intense globally and have higher rainfall rates than present-day hurricanes."
Meanwhile, a 2018 article in Nature Sustainability reports that normalized losses due to hurricanes remain basically flat. The researchers "normalize" the losses by attempting to estimate direct economic losses from a historical storm as if that same event were to occur under contemporary social conditions. The upshot we're losing more buildings and infrastructure, but only because there is much more property to be destroyed along the Atlantic and Gulf coasts than there used to be. Once you adjust for that, the proportion of assets damaged by hurricanes even possibly amplified by climate change is not increasing.
[Ronald Bailey, “Is Climate Change Loading Tropical Storm Barry Up with Extra Rain?” Reason, July 12]