This one hit too close to home! Wow. My wife and I just completed replacing the entire subfloor including ALL the floor joists in a 900 square foot rental we bought years ago. It’s a 1943 farmhouse a foot off the ground. The place spent 18 months on 8 jacks while we worked our way around it twice: Once for the joists and again for the sub floor and insulation. Saved 10k just in doing the jacking ourselves. The rot from years of moist air under the house had turned the 2" thick sill plates to sponge and dust. In places we literally swept them away with a broom. At least 2 floor joists snapped when we stepped on them once they didn’t have plywood helping hold them together. Still have the scars on my shins from scraping them when the things went out from under me.