Back when I had an old flip phone (just two years ago!), it cost me 20c to send or receive a text, (as well as being super cumbersome to compose one), so I didn't like getting texts. And I couldn't have that feature without breaking my cheap legacy plan.
So it was some relief to migrate to a smart phone and have free unlimited texts. And now we are actually paying less for both smart phones and unlimited everything than we were paying for one smart and one dumb with restrictions on minutes, data and texts.
I mainly use it to receive alert texts from various financial institutions/credit cards etc., for receiving alerts about debits, etc. and for security notices, codes for 2-step verification , etc. It's super handy for this and if something suspicious happens I am notified immediately - $5000 charge on my Fidelity VISA - what?!?! Also to get status on trains/planes when traveling, etc.
But also family members send photos and messages by text rather than email. And texts are free for me overseas. And DH and I text each other occasionally - I'm just got done at the Doctor's, blah, blah.
So - it's super handy!