I think the issue is more that the tools that designers/marketers/salespeople use are moving to cloud solutions that manage versioning internally (figma/google docs/etc). It's harder to do features like multiplayer interfaces in local file-based workflows.

If SVN was so great for these non-developer use-cases, they could all still be using SVN. Just because the devs moved on to git, doesn't mean that SVN was made unavailable to these people. TortiseSVN still makes releases.