It becomes relevant during a divorce, or a capital gain or loss that has expenses related to the basis. Sometimes it's to your advantage not to have the documentation, but those situations are often zero-sum, so the other party will go the extra mile to find whatever is missing.
Maybe you live elsewhere, but in the US it's common for statements to be available for only seven years, and if you close an account, its online statements are gone for good. Bad marriages and good investments can last far longer than that.
Yeah, that's the right number, but the context is slightly incorrect. If in 2022 you claim a lowered capital gain based on a home renovation you did in 2001, then you need to save those 2001 receipts for seven years, i.e. until 2029. The date on the receipts doesn't matter; the seven-year clock starts ticking only when you involve them in a taxable event.
