Samsungs can’t do VoLTE in customroms (there’s threads that explain more, some nuance on used SoC, but it’s “mostly”) - so you’d rely on 2G voice calls to be possible still with your provider.
That 2g option gets phased out increasingly, depending on country and provider (what do you use?).
(when I used a phone without VoLTE, friends and family adjusted when seeing me using Signal for calls and I had a SIP client for everything else)