Are clicks a good advertising KPI?

No. Aside from a few obvious tactics like paid search and native, there is ample evidence to avoid optimizing your advertising for clicks.

In short, it's expensive, ineffective, and distracting. Is there any more to say? I've already explained why you should ditch the mid-funnel section of your media plan, so let's throw clicks a going away party also and focus on better metrics…literally any other metric in the short term, but you should be thinking about running experiments to figure out which one correlates best to business outcomes. If you want to talk about your campaigns and get a recommendation for that short term metric, get in touch! I'm happy to help you through this bump in the road.