I’ve been using GrapheneOS for at least 5 years now (still remember the days when their sandboxed Play Store would need a force stop after every app install 💀) and I’m a much heavier user than you (social media, YouTube/podcasts, etc.). At this point I would not use anything else.

You won’t have issues with app compatibility except for certain banking apps and Google Pay, if you choose to install the sandboxed Google Services. If not, you’ll have issues with some apps not sending you push notifications (for example, Discord and Proton Mail) and other apps not working entirely (like Snapchat). Still, the last time I tried going fully de-Googled I remember most apps still working well enough even without Google services. From your post it sounds like you could easily live without it.

Sadly the newer phones have no headphone jack, and you definitely should not go for older ones that don’t recieve security updates. And the Pixels have never had removable batteries (you can check out iFixit for more info on repairability). Any Bluetooth headphones will work. They do have a 3.5mm jack to USB-C adapter but I it never worked for me.

Data transfer between Linux and Android has always been dead simple regardless of the OSes involved. Just plug the phone in and tap a couple of things, the phone’s filesystem will show up on the PC like any USB drive.

I use GrapheneOS on a Pixel 8a. About 6 months in. The recent “a” series models are a pretty good deal as they come with 7 years of updates from initial release.

I love GrapheneOS. Pretty much just works. Many Apps do not even have to have google play installed. There are some apps that may not run. Typically those that require an original authentic device. My banking app did not run originally but now it does. Not sure but I think I had issues with the UPS app for some reason. I switched to the web for that.

As long as your headphones are Bluetooth, they will continue to work fine.

I haven’t run Graphene OS since I broke my Pixel 3a and went with a different device. But when I did run it, it was perfectly fine.

With that said, I ran lineage before I ran graphene and I ran lineage after I moved away from graphene.

Headphone jack:

Get a USBC adapter

Batteries:

Not easy to change, check out ifixit

Debian <> Pixel data transfer:

USB, or Wireless across any protocol you can imagine.

My experience with GOS:

Contactless payments and some QR code payment methods from banking apps in my country refuse to work with GOS.

Otherwise, I love it. Very easy to install and use. Recommended.

My main OS is debian. How easy is to transfer data from GrapheneOS to debian and the other way round?

KDE Connect works great for me

Ive used grapheneOS for a few years, and I also used calyxOS. If you’re looking for maximum security, go with graphene, if you’re more of a beginner and need easier usability, calyxOS. Both are great but graphene does require more tinkering IMO if you’re worried about that sort of stuff

You should probably also consider CalyxOS, which supports most Pixel phones and, for me at least, seems to work with banking apps using microG while removing all of the pre installed Google bloat and providing a firewall.

That said, I haven’t tried GrapheneOS. From what I hear you can lock it down even more and there are more features.

Head phone jack. My 8a sadly has none. Not sure any recent Pixels do. I use combination of some HP OTC hearing aids and a Senhouser headset, both blue tooth.

Files transfer. I mosly use Nextcloud or just plugin my phone to my computer directly with USB. I have used syncthing and ssh too. Debian should work but I have more experince with Ubuntu and the USB method works fine there.