They have a pontoon bridge already setup along that bridge and numerous other supply routes, including air and train, and its not as if the superstructure was damaged, only the tarmac, which takes less than a day to fix. The most crucial part, is that it illustrates that Ukraine has no intention of ever using that bridge to go to Kherson, and since they need the bridge to take Kherson, it's clear that Kherson will never be Ukraine's again.