They’re not super common. I don’t see one every single time I go grocery shopping, though I would say typically there are maybe one or two recalls posted somewhere in the store at a time. Most I’ve seen at once is four, maybe a year or so ago, but they also keep the signs up for a few weeks so they didn’t happen all at once.
They do always have either a picture of the product or at least the name prominently placed, so you can glance at it to see whether it’s about something you might have bought.
I know experts say this doesn’t fundamentally change anything, but this sort of stuff still scares the shit out of me. There used to be a subreddit called UkraineAnxiety but they shut down with the Reddit protests last year. Really wish there was a resource like that now, because most comments I’m seeing are nonchalantly joking about nuclear war and that’s not helping…