I don't think age and use is relevant when it comes to mitigating risks of leaks. If moisture has an avenue to enter a coach (no matter how new or old the RV is - or how often it has been used), destruction of build materials begins.
Wood floors, walls, ceilings, and framing are all suseptable to water damage if an entry point exists. Exterior sheathing, fiberglass walls, front caps, and roof membranes are the only components meant to get "wet". When moisture finds its way beyond that, interior floors, walls, and roofs will rot in an inconspicuous way. The rest of the coach will look untouched.
Rot is inevitable (and potentially accelerated) in conditions where components are subject to trapped moisture. Identify and fix the entry point of this moisture before the repair work begins on your floor.
2017 Keystone Bullet 308BHS in Saddle.
2017 RAM 2500 Laramie Mega Cab 4x4 Hemi 6.4L
2008 GMC Yukon XL Denali (SOLD)
Hensley SwiftArrow Control Hitch with 1000 lb Spring Bars
Me, DW, (3) little DS's, and 1 rambunctious Boston Terrier