Instead, I installed CalyxOS and have been using it over a year now and I'm very happy with it. Check it out.
Unfortunately, Rossmann turned out to be very dishonest, which in retrospect makes sense, seeing as he has no issues with using Kiwi Farms. He's verified account there is named "larossmann". I suggest you look into it.
It's not just something he's done with GrapheneOS and the founder of the project. There are many videos, such as the one he did on Linus from Linus Tech Tips where he similarly misrepresented things and ascribed mental health labels on them.
Regarding CalyxOS, I would recommend people check out https://eylenburg.github.io/android_comparison.htm as a third-party comparison for various projects, including GrapheneOS and CalyxOS. They're not similar projects.