Thoughts on dental sealant on kids?

Dentist made us an appointment for my six-year-old to get sealant on his molars. Never had a cavity, good oral hygiene. Is this a money grab? Putting permanent plastic coatings on a kid’s teeth just doesn’t seem like a good idea…

Edit: Thank you for the responses, I appreciate it! Seems like a pretty unanimous yes, so I’ll be keeping the appointment and getting his sealants. 😊