Also I forgot to reply to this on the other answer, but:

Err.. You often don't have the files drm free on Steam. Nor in an installable format (without steam).

Often you do, and an installer is nothing more than a fancy zipped folder. Also people usually like to compare Steam with GoG and claim that on GoG you get DRM free games and not on Steam, that is not true, both have either, although GoG has percentually more it's still not 100% DRM free (nor is Steam 100% DRMd), it's always up to the game developers.

This is what you said:

While that may be partly true, (also likely) depending on the county you're located, they're not able to revoke the license though.

The same is true for Steam, laws are laws

So in this specific case you having the files makes a world of difference.

You also have the files if you downloaded them on Steam. What's important is whether those files can be used on their own or if they're protected by some form of DRM. If the files can be used on their own it doesn't matter if you got them from Steam, GoG or a physical disc. If on the other hand the files are DRM protected you having them is useless, whoever controls the DRM controls your files, again regardless of where you got the files from.