If I have a job that seems fine, and a recruiter I’ve never met contacts me about some job that seems no better, or clearly worse, why would I respond (if I do)

If I have a job that seems fine, and a recruiter I’ve never met contacts me about some job that seems no better, or clearly worse, why would I respond (if I do) with anything more than the canned reply of no interest? Anyone else here feel like interviewing every time a recruitment pitch comes in?