What does your mobile phone setup look like?

My approach is to try to use my phone as little as possible, no particular setup. Before you root your phone, mind the fact that some banks will not let you use Mobile Banking which for me is very inconvenient. This made me unroot my iPhone since there were no Cydia Tweaks for my bank app, but I regularly save my SHSH2 blobs just in case something decent appears and I get passionate about rooted phones.

You can consider the idea of not using a phone at all, which may be the most aligned with what seem to be your values regarding tech. If you don't, then look into phones on which you can install LineageOS or even PINEPHONEs.

Mental Outlaw[1] has some helpful videos on YouTube on some of these topics.

[1] https://www.youtube.com/watch?v=ThsXFPC-_60

For media consumption I decided to go with Plex. It's not open-source, but it works well enough for me. Maybe I'll switch to Jellyfin at some point, but for now I'm satisfied with Plex so it would be more trouble switching than my time would be worth.

It let me put my own library of Blu-Rays I ripped myself, as well as music I purchased over the years (many CDs I ripped myself), and more recently purchased through Bandcamp. Having it easily accessible from anywhere is good enough for me.

For mobile apps, I prioritize apps that are published on F-Droid, and will fallback on closed-source apps if nothing fit my requirements.

It is not a solved problem, unfortunately. That is why you see so much interest in the likes of PinePhone - even a rooted and de-googled Android doesn't really give the same feeling of ownership and control as a standard GNU/Linux system. At the moment, the most practical thing to do is to pick whichever Android phone you find most physically appealing that also has LineageOS builds, scrupulously avoid any Google-made software (including and especially Play Services), and try to use it as little as possible. Keep the phone as a satellite device. Install KDE Connect so you can conveniently transfer photos and other data to a more suitable platform, and F-Droid so you can still tinker with apps. Expect to miss out on most of the usual closed-source apps - most are only distributed on Google Play only, and you can't have that without handing root to Google. Finding a phone with the physical properties you describe shouldn't be difficult, although expect to have poorer LineageOS support the more obscure it is.

If you want a pocket device that truly gives you the same feeling as your desktop, and is immensely practical at the expense of not having mobile phone access, I can fully endorse the GPD Micro PC. Since I got mine, the phone only gets used for phone calls, navigation, and photography. I generally keep the phone on hotspot when I go out so the Micro PC has connectivity.

I'm using an old Samsung candy bar phone, with no camera, no internet, and no apps. I have zero fear of it being hacked.

Some day I'll be forced into a smart phone, but it hasn't happened yet. When it does, I hope that phone is running Genode or Fuchsia.

I use a Moto G7 Power with Lineage. I have the minimum Google services required as the push notifications weren't great without and battery usage was higher.

For cloud services I use: Migadu (email), Nextcloud (Caldav, Carddav, Photos/files sync), Spotify. Most of my instant messaging is thru Signal, I think Matrix is too "out there" for my friends and family.

iPhone 7 Plus, iCloud for backing up photos, a pair of AirPods Pros, Spotify, and that's about it.

It all works wonderfully well. At some point, I might upgrade to iPhone 13 or 14 (whichever one they just announced), though I don't really need to. For e-mail, I just use the default Mail app. The battery life on this thing, after ~4 years, is surprisingly great. The Settings app has a menu that tells me my battery holds up to ~89% charge. Good enough I think.

What I really like about the AirPods is I can really easily switch between my MacBook and my iPhone. And the one time I misplaced them (leaving them in the office), I was able to quickly figure out where they were using the Find my app.

Pixel with self-compiled ROM and F-Droid userland.

Nokia 3310