Why only for these "desktop" socs? Why couldn't Qualcomm partner with Debian/Ubuntu to bring support to their mobile chipsets? Why can't Qualcomm partner with PostmarketOS to help recycle old devices and avoid e-waste?

Well, in case anyone else is wondering, I have the answer. That's because Google is maintaining a cartel, the "GMS" cartel in short. Due to intense lobbying and incredibly weak antitrust enforcement, this cartel still continues to operate globally, keeping soc makers like Qualcomm, Mediatek and Unisoc in chokehold. We won't see any real competition in the smartphone space unless it's destroyed, but market forces alone can't do that.