In the case of natural disasters use titanium washers or if you can't afford it due to budgetary constraints then use Stainless Steel Washers. Not just any Stainless Steel Washers but grade 316 stainless. Titanium may not be readily available because they are generally more expensive but Stainless Steel Washers but grade 316 are likely to provide better overall protection due to their superior corrosion resistance, availability, and cost-effectiveness. Whichever the individual chooses, they should go ahead to create multiple copies of the seed phrase backup and store them in secure locations. They are very trusted locations that these copies can be spread across to minimize the risk of all backups being destroyed by a single disaster like flooding or earthquake.
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 local 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. Also the disaster can be worst like earthquake that destroyed a building on a way that nothing can be seen again.