I sorely miss DivestOS for this purpose, but I'd consider CalyxOS (development sadly on pause) ~~and iodeOS~~ as runners-up. /e/OS got caught sending voice-to-text data to OpenAI, so I'd stay away for the time being.

edit: sad to see that iode has a freemium model on some of its features. see replies for more nuance on the /e/OS situation.

LineageOS will get the most years of support out of the most devices. While leagues ahead of Android for privacy, bear in mind that it still isn't airtight with regard to the occasional piece of telemetry data sent back to Google. It's about the only thing that can keep one of my older Pixels somewhat up-to-date.

LeOS is like LineageOS with all Google telemetry stripped out, but only in GSI form (no builds optimized for specific devices), so YMMV with hardware compatibility. I have this on my Samsung tablet.

I've also heard about Volla Phones (with VollaOS) and Brax Phones (with iodeOS or Ubuntu Touch), but haven't taken a serious look since the screen sizes offered are too big for me.

I might try out a Linux phone next, but the relative lack of battery optimizations and edge-case issues leave me a bit hesitant. Also, check out detailed comparison of the common Android ROMs with regard to privacy and security: https://eylenburg.github.io/android_comparison.htm

GrapheneOS is the only one cellebrite admits it has trouble with, I can't recommend another OS, but I can say that being resistant to the government hacking your phone has recently become more important and it might be worth reconsidering.

LineageOS and the companion microg for LineageOS is a good alternative. They offer a wide variety of phones (and some tablets) that are supported. Been using microg for LOS for over 5 years now with no major issues.

Why not install LineageOS on your S20?

You could buy a used Pixel, if you don't want to support Google.

pinephone or a H.A.M radio

Sad that there are no Linux phone versions for the Xiaomi brands, they're good, resilient and powerful for their price IMO.

If you want a new phone consider /e/OS as you can directly buy a phone from Murena (who maintains /e/OS) and thus get something working from day 1, no tinkering.

To clarify, because there is constant FUD around /e/OS (I think the deGoogled Android crowd is VERY passionate and invests a lot of effort into picking the "right" ROM for them leading to a kind of "holy war" which tends to lose focus on what actually matters, namely leave Google!) so to clarify

• /e/OS is not Murena
• Murena is the French company that sells phones, including refurbished, running /e/OS
• /e/OS is open source https://gitlab.e.foundation/e/os/
• services from Murena are optional, including STT (which is a premium service) and anything cloud based requires Murena accounts
• one can buy a phone from Murena and not using any of their service, it's as straightforward as NOT creating an account when booting the phone the first time, or not using an account, that's it.

Honestly I recommend this solution if you want a good compromise because IMHO

• Linux phones, e.g. PinePhones (I have 2, cf post history for details) aren't daily drivers yet for most
• it works, simple as that
• it's quite affordable, you don't need a flagship to run /e/OS
• it is actually deGoogled Android, which is IMHO the whole point
• depending on your bank you might be able to use their banking app

Feel free to ask questions, happy to clarify.

The Furi phone runs a version of Linux and has decent specs

Check out UBports/Ubuntu Touch, it’s a linux-based OS with a neat desktop mode when docked.

No one else knows about iode os?

https://iode.tech/iodeos/

I am curious to why no google Pixel?

Would anyone know of a custom ROM for an Oppo Reno 4 Pro? Looked everywhere, can't find one.

/e/OS has similar goals as Graphene (not exactly), but it supports many more models than Pixels. Check their list and see if it fits your needs.

CalyxOS , though updates are temporarily paused for unknown period , you can get Fairphone 4 or Fairphone 5 , if privacy is your main concern and you don't mind downgrading