Titanium or stainless steel or steel or any good metallic storage is also not 100% safe because flood can move the storage from your location you store the backup to a very far place like a place that another person will be the one to see it on maybe the flood can move it to a river a place that people can not get to it. Also the disaster can be worse like earthquake that destroyed a building in a way that nothing can be seen again.
I agree that Titanium or stainless steel or steel storage methods for seed phrases doesn't offer 100% guarantee. No storage method does. Here's my point, these metals are designed to withstand flooding and remain intact even in the event of earthquakes or building collapses. Secondly, in the event that the flood moves it away from its location, there are identification markers or tracking systems that can be use on the storage can which can aid in their recovery. Therefore, if we live in areas that are prone to such disasters, we should live with disaster preparedness and recovery plans in mind. These plans should include measures for securing and protecting backup storage locations which have already been stated, as well as procedures for data retrieval and restoration in the event of a disaster. Lastly, because these disasters do not happen simultaneously across a whole country, we should secure them in multiple storage locations.