Extending the life of clothes by just nine extra months of active use would reduce carbon, water and waste footprints by around 20-30% each.
Notes:
Research is behind a paywall.
Primary Source:
https://www.wrap.org.uk/content/extending-life-clothes
Secondary Source:
https://www.businessoffashion.com/articles/professional/is-resale-actually-good-for-the-planet