While banning such payments might remove the incentives, that also put a huge burden on the victim and the transition to better cybersecurity should be less disruptive than an outright ban.
Another solution that has no harms and only benefit is to require the reporting of every ransom payment. That would give the government the crypto transaction information to conduct taint and attribution analysis. It is currently illegal to knowingly use funds received from kidnapping or ransoms, and this reporting requirement would help the government enforce that.