As things stand, there's a difference between purchasing for personal consumption, and for publishing. That's been standing, for a very long time. It might be as old as copyright itself.
Just because you own the game, doesn't mean you have the rights to use it in more than a personal setting. That's basically always been the case. You bought a personal license, not a broadcasting one.
The main reason for not attacking such things in the past was that it was a wasted effort at control. Too small a target, requiring too much effort. Automation, through things like audio recognition, changes that.
We've had the capability to detect audio for a long time. What changed suddenly in the last few years to deploy/enforce this at scale? Certainly not any improvements to detection. I've made a whopping total of $46 in something like 12 years on these platforms. Something tells me this level of enforcement is ridiculous and against the spirit of the law, and I'm certainly not an expert on the DMCA or a lawyer, but I'd be willing to wager a lot that this strict interpretation is misinterpreted. No one is submitting any takedown requests to this content, which to be clear, averages like 1.3 viewers and has less than a few thousand follwers. And when I describe in-game audio - I mean literal 2-3 second song clips like "barbie girl" song happening when you score a goal in rocket league will get your VOD DMCA'd and you can't upload it to YT. That is a newer thing. You really can't view the last 20 years of DRM and the way it's played out, and say something like "this is how it's always been, now automation." That doesn't add up.
Someone invented a system that makes it trivial for bottom feeding lawyer types to send frivolous notices. They feel like they've accomplished something.
That's the long and short of it. It suddenly became trivial to do and the consequences won't be apparent for quite some time, so there are no consequences as far as the lawyers and accountants are concerned.
A modest proposal: sell "streamer" licenses for a game that include audio/video watermarking features, or require an active internet connection and redisplay a sequence of numbers like a security key over the corner of the screen. Any footage without this would be taken down automatically.
Publishers could charge upwards of $200 for these. Larger publishers could offer package subscription deals for you to be able to stream content from their games.
Some governments [0] and IP holders [1] already offer this.
There's some back and forth about the exact underlying licensing, without an industry standard just yet - free streams are sometimes exempt, or require a partial license.
Just because you own the game, doesn't mean you have the rights to use it in more than a personal setting. That's basically always been the case. You bought a personal license, not a broadcasting one.
The main reason for not attacking such things in the past was that it was a wasted effort at control. Too small a target, requiring too much effort. Automation, through things like audio recognition, changes that.