What are you talking about? You're making zero sense. I've been in the niche of modifying and installing my own ROMs, then to kernels, and now doing the same things commercially.

It is a niche, it always was. There was never a mass community of users, the most installs you used to see on any given AOSP based project is maybe 20-30K for the most popular devices like Redmis, Pocos or Google Nexus phones.

It's still a niche, and things that users do and used to do to their phones are fundamentally incompatible with Android's security model. Root access, magisk, xposed, overall zero or near zero security validation from the security perspective on all ROMs but Graphene (maybe some others, I haven't followed the sphere for a while).