At least 3 times a month. I have a rental property and my tenant prefers to mail a check instead of paying extra to pay electronically. My spouse gets paid by check for dumb reasons I won't get into. I sometimes get dividends from my insurance company via check. And then several family members still prefer to use checks to pay each other back instead of Venmo or other electronic services.

I blame it on the fact that the US doesn't have a free electronic bank transfer system like the rest of the developed world.