Call buttons only show when someone's actually there to answer.

You search for a plumber on a local business directory. You see a big call button. You tap it. Nobody answers, or you reach a voicemail, or you get routed to someone who doesn't do plumbing.

The directory had call buttons for every type of service, even when no actual plumber had signed up yet. It looked helpful. It wasn't.

Now the call button only shows if a real business has signed up and confirmed they work in that category. If nobody's signed up yet, you see a link to find them on Google instead. You're not chasing dead ends.