No, AT&T sunk to the lowest all-time low when they created their 'whitelist' of compatible handsets they let you use after the 3G sunset (which still hasn't happened as I have an active 3G tablet on them that still has bars and H+ data). A lot of perfectly capable VoLTE-compatible handsets are blacklisted. Try placing your SIM into one, it hotlines it and you can't use the account. Try keeping an already active phone around, and ignore their texts begging you to trade in your unlocked Note 10 for their garbage tier AT&T 'Calypso' and you will eventually lose that account as well.
That last part is not true at all.
AT&T has provided me with free phones each time the technology has changed- all the way back to when they switched off analog service.
Just keep using your device, ignore any offers, and wait until the text saying that your device will no longer work after a certain date.
Call customer service, tell them that you cannot afford a new device, and ask them if you are eligible for a free device to maintain your service.
No, it won't be great, but it will work and it will be free.
It will even have a one year warranty.
I have done this over and over, and even helped others to do it as well.
An amout of time on the phone to get a free cellphone for me or another person is time well spent in my opinion.
Plus, it's kind of fun for me.
The last time, there was disagreement over this very subject at my favored local 'watering hole', and so after the establishment closed I took a person upstairs where we could spend some time on my phone with customer service.
Much to everyone at the bar's surprise, the girl got a free phone from AT&T and a free phone (and service) from Lifeline that very week.
I thought it would be funny to get her signed up for that as well.
She got both phones, maintained the service she had from before, and also got the free service frome Lifeline.
I guess I should have made some bets, lol.
I could have drank free for a week if I bet on it with all the naysayers.