Are there still no VOIP services like Google Voice and Textfree? iOS 6

So we all know that iOS 6/32-bit devices don’t have any 4G support, the iPhone 5 supports LTE but it doesn’t support VoLTE, meaning you can only send text and use data if you try really hard. Some years back, a few VOIP services such as Textfree worked, but they no longer do. Are there any VOIP services that work on iOS 6 in 2025? I wanna daily drive my iPhone 5 because the skeuomorphic design makes me really happy, but I still wanna be able to do calls in some form. If not I can just use my real phone only for calls, thanks!