That does sound pretty useful. What is the subscription cost of such a service? Or is it a front-end cost for the software?
I don't really work with the Microsoft stack anymore, and don't know what all of TLG's requirements are. This is generally the sort of thing a company might bring a consultant or solutions provider in for. I only mention it as an example and don't necessarily recommend Sharepoint in particular. It's a "platform" for building other products and solutions, so there is no upper bound on what you can end up paying.
It can vary a lot. Sharepoint Online is $5 per user per month, not sure about additional costs. I've only worked with earlier versions and wasn't the one doing the buying. You can pay far more for it than that if you require a custom solution beyond what it does out of the box, if you want to host on your own servers and databases, if you want to integrate with other software. It can require some training also, depending on if you intend to make the most of it.
Nuxeo is an open-source offering that does similar things. Again, it's a platform; to get the most out of it you build a custom solution for your company on top of it.
"Digital Asset Management" and "Content Management" are the keywords you'd look up to find products and services of this type.
As expensive and involved as this can get, it's no wonder smaller companies don't jump on this stuff.
One thing I saw while researching; dropbox does support some kind of versioning; I didn't know that as I don't really use it. I'm not sure if it's comparable to what these other solutions offer.