I don’t bother with local cards, work colleagues, people I see every week, that sort of thing.
I mostly send cards to old friends who live a distance away - people I was at university with, or worked with, who I literally don’t see from one year to the next. It’s not because we fell out, but life is busy and time passes quickly, we all have jobs and kids and elderly parents and so on, and finding time to actually meet up is virtually impossible. These are people who I spent time with before social media and mobile phones, so half the time I don’t have their mobile number, and they’re not on Facebook.
So once a year I write them a few paragraphs in a card. I update them on my work, my kids, mutual friends, general chat, a few reminiscences. I often wondered if people cared or even read my cards, as the ones I get back are generally just a couple of lines or even less. But I carry on anyway.
A few years I saw a few of them at a funeral, and they made a point of saying how much they liked my cards, and looked forward to reading them. So I’ll keep on doing it. I’m not expecting others to do the same, but I do always feel slightly disappointed when I open a card hoping for some news, and just see “to X, happy Christmas, from Y.”
Each to their own I suppose, but I personally wouldn’t waste the money on a stamp if all I planned to write was a couple of names.