Yeah, but it's not standardised because its output is so close to "bare metal", it's wrapped into a standardised format a few steps later when a JPG/HEIC/... is created.

Supporting DNG means that those few steps later it should be standardised into ANOTHER RAW-equivalent. A format which happens to be patented and comes with a license and legal implications.

Among them the right for Adobe to every method you used to make this conversion from your proprietary bare-metal sensor-data. This is not trivial, because if you're a vendor working on sensor-tech you wouldn't want to be required to share all your processing with Adobe for free...

I have no knowledge of DNG, what I was suggesting is that someone should devise a some kind of extensible, self-describing format that can be used in place of RAW without losing any sensor data as with JPEG/HEIC/etc.