I was hopeful about lots of alternatives, but Firefox OS is dead for now and Sailfish is hard to come by without rooting.

Rooting your phone isn't always possible. Microsoft controls both CyanogenMod, which is often the best opption, and of course Windows Mobile, but in many ways MS is actually more open source friendly than Google nowadays. (and both are obviously way more open than Apple)

Honestly, I'm rooting for Microsoft in the mobile space right now simply because the more competition there is, the more need for cross-platform standards.

But I'm also rooting for Sailfish and Firefox (assuming they try again when Servo is done). They all have interesting pros and cons.

Cyanogenmod is now just a defunct brand - the spirit of the thing lives on in the LineageOS fork (sans corporate backing).

LineageOS https://www.lineageos.org/ + F-Droid https://f-droid.org/

LineageOS's security story is appalling though.

https://cve.lineageos.org/kernels is their tracker for CVEs in non-deprecated kernels they ship in officially supported devices: no kernel they ship has 100% of CVEs patched, and both mean and median are about 49% of CVEs patched. And this is before we start even considering the firmware blobs that are shipped that haven't had security updates in years.

Plus, you have to execute non-reproducible binaries in order to install LinageOS on your phone.

Bizarrely, clicking on "Downloads" for LineageOS takes you to what looks like a bug tracker and is actually a changelog. Yes, you click for your model in the left aside, but it sure takes some figuring out.

Yeah, the homepage could definitely use some improvements.

Does LineageOS integrate google apps/services by default?

No, adding "gapps" is an optional (unsupported) step after imaging the device.

CopperheadOS for both security and privacy. But device support is limited to the Google flagships.

Support Ubuntu Touch. Open Source linux!

Sailfish OS