So, I just learned about this the very, very hard way.
After buying a second hand S10 and finding american ones can't be unlocked, traveling 4 hours to buy another one after much research, much annoyances to unlock it (samsung requires you to be online, which I didn't know) and testing multiple ROMs, I finally read this page more properly https://wiki.lineageos.org/devices/beyond1lte/ which says "known quirks: IMS". I thought it was just something like dolby sound.
What it means is that it doesn't suport VoLTE and most currently used phone systems. Samsung made their proprietary mess, unlike most other developers, which means it will probably never have an open source version.
And that applies to ALL modern samsung phones. I had samsung phone before with a custom OS, but didn't realize because VoLTE wasn't mandatory back then. Now it is here in Australia, and many countries. So if you ever plan to buy a samsung phone to degoogle it, know that it won't make phone calls. SMS and mobile data also doesn't work.
I don't know how I missed this. It should be talked more often given how popular samsung is. There should always be a warning "YOU WON'T BE ABLE TO MAKE PHONE CALLS IN THE FUTURE IF YOU CONTINUE".
S10 was the last decent phone ever made (for me). Not too big, SD card, headphone jack (one of the most important things for me), good camera, etc, etc... That's why I was so persistent to find one to degoogle.
So I'm stuck with my amazingly shitty pixel 5 (and other ones are even worse for me). And considering the possibility of a life without smartphones at all, since this is a losing battle. Mainstream doesn't care and evil companies have every incentive to kill freedom. It has been getting really bad and it will just get worse. But anyway... this post is not about this.
Be warned, if you care about freedom don't ever buy samsung again. Not because they are evil (they are), but because you won't be able to make phone calls on your "phone".
Yeah, technology enshittification as a whole has definitely picked up the last few years, and I find myself compromising more and more as the field of reasonable options gets narrower.
Like you, I used to only go for phones with SD card and headphone jack support. Now, I'm on a (new but not bought from Google) Pixel 9 Fold with GrapheneOS using a DAC adapter to still have wired audio and a more deliberate storage management system to compensate for not having SD cards. (Unlike you, I need a big screen for spreadsheets and such.)
I purposely bought the newest phone I could within my budget, because I'm planning for Android to be completely unviable the next time I need to upgrade, and I want to give Linux phones as much time to mature as possible before I inevitably migrate.
It seems offline tech is going to be the last bastion of safety sooner rather than later, so I'm in various stages of migrating my digital life offline. Linux over Windows. Keepass, LibreOffice, Obsidian, etc. + Syncthing over cloud options. Keeping off-site backups with friends and family instead of in the cloud. Keeping local DRM-free media. It's time-consuming but rewarding. I should have done it all way sooner.
I have been on the offline open source route for many years. I don't even see it as time consuming. It's so much better than relying on cloud services that it pays off. I lost count of the situations where needing cloud would have been bad. But maybe I trained myself that way, because I never liked the "cloud" idea, my data out of my control.
But the hardware to run that and the options to do that will become more and more impossible. At least on mobiles.
There will come a day when Syncthing won't work anymore on android, because of "security" (the terrorists could send files to your phone and kill children!).
Funnily enough, I've thought of the cloud as "someone else's computer" from the beginning and shun using it more than everyone else I know, but I was just getting into the space when Gmail and Chrome were the hot new things, each gradual step into the ecosystem didn't feel like a big concession, and I was too young to know to question the convenience.
In case it wasn't clear, reversing those two decades of inertia and tech debt is what I was referring to as the time-consuming bit. So far, what I've finished switching over is actually quite nice to use.
And yes, I dread the day even the fallback options start getting killed off. It's always one bad law away.