Despite all the wonders of technology, sometimes we need to speak to people who aren't in speaking distance. We've come a long way since Alexander Graham Bell.
Mobile phones have become pervasive, but we may not be the only ones who live in areas where signals are not always great. We switched to Vodafone soon after they arrived, but surprisingly when we tested the signals recently we found they were the weakest in out area. We added a second SIM (our phones aren't locked to a provider) for 2Degrees, buy have now switched that to Warehouse Mobile who use the 2Degrees network but at very cheap rates. (They also offer free calling to others on the network - great for husband and wife, etc.) We've also switched the Vodafone number over to Skinny (who use the Spark network but have cheaper rates, although nowhere near Warehouse Mobile).
Skype has been providing a great service for many years, but uses a lot of bandwidth and made some sad choices when Microsoft bought them. We have been using Teamviewer to help clients on their computer, and that allows us to use audio as well. Sadly they too have made an unfortunate (but common) choice, so we are currently trialling Zoom.
Land lines are being phased out, but the same service is available through the internet at great prices. We have been using phones over VOIP for some years, and the options are much better. Our ISP we changed to with fibre offered phone services through a third party - but although we love our ISP, we had issues with the phone. Now we are with 2talk, which we highly recommend. You can even set it up to come to your mobile through data if you want - great when we go out. Also useful if you move areas but want to keep the same number.