There’s an important note. Verizon (and other American carriers) have no plans on shutting down 4G LTE. Even with c-band and DSS there are still large swaths of the country without any sort of 5G. In addition, devices a as recent as the iPhone 11 from 2019 do not support 5G.

The major American carriers are shutting down 3G. But for that to be a problem you’ve got to go back to the iPhone 5s, which has LTE data, but not for voice (going off the top of my head there, might be a generation off).

Maybe fairphone 4? From factory it comes with android 11, but a beta release of /e/OS is now available for it [1].

[1]: https://e.foundation/leaving-apple-google-e-os-is-available-...

Some of the newer OnePlus devices have postmarketOS support, and they all have LineageOS support. However, I've heard that the latest OnePlus phone's 5G doesn't work on AT&T for some reason. Not sure about the other carriers. It seems like a bad time to get a 5G phone. Hopefully things are better in a few years.

There is no such thing as open smartphone. Legally you are not allowed to transmit, unless you got liscence. So baseband will be always locked. There are some dumb phones that can thou.

Can't you just buy a Pixel 6 and put Calyx on it?

EDIT: Also, Verizon has no plans whatsoever to shut down their LTE network.

What are the advantages of Calyx versus GrapheneOS?

A 'secure OS' which comes with a built-in VPN doesn't sit well with me (CIA says, pls send all ur traffic over our 'uber secure' tunnel kthx kek), and it seems Calyx isn't as technically adept as Graphene when it comes to kernel & library level exploit mitigation techniques.

The history of GrapheneOS is quite funny btw, when it was called 'CopperheadOS' the actual dev mic-dropped and deleted the signing keys stating that the business guy was compromised. Remember, the business guy was making people physically send their phones to HQ so the OS image could be 'securely installed'.

Also the VPN in calyxos does not appear to be enabled by default. You don't have to use it if you don't trust it.

I like both projects and they both have their place. My understanding is:

-Calyxos is less secure but more usable day to day, since most apps work. -GrapheneOS is more secure but less usable day to day since major apps don't work.

Nearly every app I have tried to run on GrapheneOS has worked fine.

Yup, sandboxed google play works fine on graphene.

And everything is neatly locked into individual user profiles.

I think he is confused by Verizon shutting down their 3G CDMA network this year. Which should have no effect on any phone that supports LTE and VoLTE.

I have a Samsung Galaxy S4 in premium condition that is definitely 4G capable but I received a letter from Verizon stating it would cease to be able to make phone calls or send text messages sometime before the end-of-the-year.

I wouldn't underestimate them to implement business measures to make certain models obsolete without any legitimate technical reason.

Remember, Verizon was a staunch proponent of CDMA adoption across the USA because it ensured vendor lock-in and non-portability across carriers. Yay capitalism!