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".
Kind of similar. Yeah, replacing everything took me a long time too and a lot of research. And I was one of the first gmail users, had dropbox account when no one knew what it was, etc etc, so I was pretty stuck. I was all google when I believed their "do not be evil" lies.
But I started the move very early too, after Snowden leaked the PRISM crimes. Back then I thought everyone would do the same and try to rely less on the cloud or, at least, stop using american companies. And oh boy, was I wrong...
If I had waited I imagine it would be a lot more difficult. I always kept my mp3, movies, porn, etc offline, but it was still easy to rely on gmail, youtube, google maps etc.
Anyway, good on you. You will find it surprising that you ever thought it was difficult after you've been detoxed for a while and end up being exposed to google products again. It will make you wonder how anyone actually put up with it.