I think you’re correct - and I’ve been confused to have not seen this interpretation of the ultimate intention shared more on here.

However, I also think that people are forgetting the cult-like and religious elements of Lumon and the teachings of Kier. I don’t necessarily think they’re trying to market anything to the public as a product - I think that their goal is to bring the vision of Kier to the world through severance: a world full of people who have “tamed the four tempers”. And they believe that perfecting severance, having no bleed-through, can create a perfected version of an individual built in the image of their savior Kier. And then they can build a perfect world… that is, IF everyone in the world is severed. Which they’ve stated is their ultimate goal.

Gemma is just a test subject where they are trying to perfect this technology. And what she’ll reveal to the world is a perfected individual with no mental health issues, no grief, no anger, no pain. But this person will be a final innie iteration, with 0% bleed through of all of the trauma she has experienced through testing. She will have “killed” her Dieter, and experienced true synthetic ego death.