I just tried satellite connectivity on my Galaxy s25 and it worked surprisingly well. It got connected to satellites while I was in my car driving through a forest in the PNW and was able to text via Google messages. Most of the time the message sent immediately. I was able to send pictures easily as well.
I also got Google maps and All Trails to work when I was out in the open. Didn't try those in the car but they probably would have worked.
WhatsApp is supposed to work with calls but I don't use that app. Hope they get Google Voice and Gmail to work sometime soon.
I'm paying $10 a month (auto pay) as a non T-Mobile customer. That includes 50 gigabytes of data use per month but blocks making phone calls through the phone app, but I can make and receive phone calls via Google Voice just fine, via cell towers. And I can use all my other data based apps as well with cell connectivity. Pretty good deal!
I tried this service on my S 20 ultra but it didn't work. It's supposed to work on the s21 and later models though, as well as many other recent phones.