Holding a control and proving it are two jobs. A policy that exists but cannot be dated is hard to lean on when somebody asks when it took effect. The same goes for training that happened before a workforce member opened a record, and for a vendor agreement signed before any data moved. Questions about a program tend to run backwards from a date, so the useful test to put to any platform you are weighing up is not whether it stores the document. It is whether the platform records when that document took effect, and whether it keeps the earlier version once somebody edits it.
Ask a vendor to show you three things on a live screen before you decide: a policy with its revision history, a completed training with the name and the date attached, and a signed agreement you can open from the vendor record it belongs to. Anything that cannot produce those on demand is a filing cabinet with a search box, and you will end up rebuilding the trail by hand at exactly the moment you have the least appetite for it.