Right but our entire infrastructure has been built to resist that. Most likely it'll happen at a slow enough pace that we could adapt, but just imagine if soil fungi could suddenly eat PVC pipes

Most traditional architectural techniques didn't try to resist rot so much as plan around it. I.e. have the structural integrity so that you could take out and replace parts of the building without the whole thing coming down. It's why Japanese temples are the oldest standing buildings around today

I imagine we'll have to relearn some of those lessons at some point