Non-destructive resize works on vector layers and link layers (essentially "smart objects" in GIMP). We have the capability to do this for regular layers too - just need to connect some things and change some internal assumptions about transform filters.
What version of GIMP are you running? Stable GIMP at this point (at least by our definition) is GIMP 3.2, which definitely has this feature. If you've been using 2.10 or earlier, then yeah, it wouldn't be in there.
