Some readers (and the writer) will remember when mobile phones were just there to ring numbers (or send messages). No more. Possibly you even remember the time when mobile phones were too expensive for most people, so fixed line phones were the only alternative.
But today there is a huge range of choices both of phones and of network providers. You need the latter to connect to a mobile network. At the same time the cost of the service due to a mixture of innovation and competition has greatly reduced.
Can we live without smartphones? It doesn’t seem likely. As well as reading this blog you can do a huge range of things that many people regard as much more interesting: taking pictures; navigating; checking the weather forecast; looking at the news; finding out your bank balance. There are many more options, with more to be invented.
A small catch: most services that you get via smartphones (including the ability to make phone calls) require you to pass on some of your personal data. Next time you download an app that offers a service that you have not used before, consider what different personal data it may need. Are you OK about passing that on?
In the UK you can get more information from the Information Commissioner’s Office. Other countries also have agencies dealing with this, and the European Union’s GDPR legislation establishes regulations about the use of personal information across the EU (and at present, in the UK). If you need to discuss this further, especially if represent a company get in touch.
In the meantime you might like to read the book shown here, about the implications of personal data when applied to technology (much broader than mobile phones.)

Privacy is Power (2020) by Carrissa Veliz.