I ported Android 12 on thousands of Android devices. I'm already bearing the support cost myself.
Small proof, Android 12 on 17 of devices I bought with my money to support that cost, 7 days after Android 12 is released https://twitter.com/phhusson/status/1447824974396497924
But (and I'm sure this will be an unpopular sentiment) you realize that it doesn't fully address the article's concerns about security. Nor does it provide the experience people expect from tested manufacturer updates (which are far from perfect, but still). This is not the same thing as manufacturer support. You could provide that level of support even as a third party, but it would be a lot more work and it would require the cooperation of Qualcomm and other vendors. You'd need to start a company and charge for your work to make it feasible.
This is about their profits. It's not about security, environmental responsibility, or the users. Regulatory authority exists to promote the interests of the people when the interests of the corporation's profits conflict with them.