Android shouldn't be considered Open Source anymore, since source code is published in batches and only part of the system is open, with more and more apps going behind the Google ecosystem itself.
Maybe it's time for a third large phone OS, whether it comes from China getting fed up with the US and Google's shenanigans (Huawei has HarmonyOS but it's not open) or some "GNU/Linux" touch version that has a serious ecosystem. Especially when more and more apps and services are "mobile-first" or "mobile-only" like banking.
How could this realistically happen? Developers of popular apps adore the control and illegitimate de-facto ownership that client side "trust" gives them, so they'll refuse to make apps for that platform. They'll also use said client side "trust" to block them. Thus, it can't reach critical mass to force adoption by these developers.