I dropped out of law school before ending up in tech, but my parents are lawyers, my sibling is a lawyer, a large chunk of my social circle are lawyers, and I act as a go-between connecting my lawyer friends and family with non-lawyer friends who need some legal help (and also someone who speaks lawyer fluently enough to translate to normal people). All of this is just to say that the ideas that:
1) change tracking is easy to use and universally understood
2) timestamps in document names solve the version problem, and
3) that emails traded back and forth work as a document history
does not at all mesh with my experience or with the complaints I hear from friends and family in the legal profession. Even just when I'm helping friends in software negotiate contracts, which usually just involves me, one other engineer, and one lawyer, changes pretty frequently get lost or go unnoticed. Versions frequently get mixed up (altho the blame for that usually falls on bad search engines in email clients). Lawyer friends have complained to me about conflicting timestamps and about larger documents with hundreds of changes being tracked that work slowly and are difficult to parse.
I definitely think engineers are too quick to throw a "one easy trick!" at a big messy problem like this that obviously has a bunch of social/network elements in addition to technical challenges, but saying that the current situation is functional for most participants doesn't really seem to be accurate.