Well, no. The purpose of a land line was indeed to make telephone calls, but home phones (land lines) are subject to revisionist history. For example, there is a myth that we all loved making calls and receiving them, but that was certainly not true, and to a large proportion of people being able to send a text is far more polite, less stressful and much more useful than phoning.
In fact, the number one method of communication these days is messaging, with most Britons indicating a strong preference for texting over phone calls. It is now considered quite impolite to just phone someone, unless you are close to them and unless this is an established and agreed to behaviour.
https: // yougov dot co dot uk/technology/articles/31699-most-britons-would-prefer-receive-text-over-phone-
Consumers also indicate a strong preference for companies that allow them to message or email.
https: // pr.liveperson dot com/ 2022-04-20-Hold-the-phone-87-of-consumers-worldwide-prefer-brands-that-connect-their-interactions-across-voice-and-messaging
Making telephone calls was only part of social history for a very brief time, and a phone was certainly great to have in your house for your own convenience, emergencies and for some people was in fact a beloved method of communication - but for many was often intrusive, unwanted and ignored when it suited them.
In the days of land lines people were also often simply not available and the caller then had to call back. "Sorry I missed your call, I was out" was the number one way to avoid unwanted phone interactions.
Within moments of the invention of the answering machine, most were using it to screen their phone calls.
And of course if the OP was unable to answer a text (she was not unable to do, but let us pretend hypothetically this was the case) she would very definitely not have had the time or ability to take a call.
Smart phones are mini computers and people use them for reading books, watching YouTube, listening to podcasts, booking plane seats, texting, emailing, banking and more. Phone calls are pretty much the bottom of the list nowadays.
So, no the purpose of a smart phone is not to make calls, that is just one of its functions, and one which is far less popular than its other uses, and the person who contacted the OP was using the now preferred and usual method of interaction - messaging.