>Even worse, it slowing us down from leaving Android entirely.
There are zero OSes that are 1/ open source 2/ appropriate for phones 3/ with good hardware support. There's absolutely nothing. Running Ubuntu Touch isn't a viable option. Neither is postmarket, librem, tizen, they're all terrible. Security wise, for something as critically important in our lives as a smartphone, I am also not trusting any new pet project that won't be stable for 10 years.
Sure, you might be a poweruser that doesn't care about your phone burning its battery in your pocket after 1 hour because you know how to SSH on it from your watch and put it in sleep, but that's not a viable option. Leaving Android is suicide. A large part of its critical underpinnings are already into the kernel anyways, just disabled. (although a distro running binder could be a fun project). APIs are reverse engineerable generally speaking, except for the server part of play services. But then, if your issue is "my bank won't let me access their app without play services attesting me", I have great news, you won't even have an app for it on your new OS anyways, so it will not work by default. There's already not enough people working on GrapheneOS _or_ on mainstream linux OSes, what makes you think the sitation won't be ten times worse for your custom made mobile OS ?
>We should focus our efforts on truly open platforms.
Android is one, and that can never be taken away. Google pulls the plug ? cool, you're stuck on Android 17, which is centuries of work ahead of literally anything else in the open source community. Hell, for all the shit that Google is doing, they're still constrained by having to work with other vendors: the system privileged notification receiver is swappable at build time, the recent app signing/verification system also is, because Samsung wouldn't let them control it all.