Honestly, it’s as if they don’t really want you using it. It’s a legitimate feature but hidden away and quite difficult to use. Here’s a guide on getting it set up. I’ve been using it since it came out and haven’t had too many issues, but a lot of addons just don’t work as intended.
Games publishers are in a war of attention and don’t want to compete with themselves. They won’t sell you an old game if they can get you hooked on the new version with microtransactions and DLC with no story and sub-par multiplayer.
The next point is just making the case for open source.