(Concern) This part where the gums have receded

I went for a regular dental check-up, and the dentist suggested a treatment to fill the area where the gums have receded a bit. They recommended it as a preventive measure before any sensitivity occurs. I don't have any symptoms like sensitivity.

Has anyone had a filling done on the area where the gums have receded a little?

When I went to a different dentist, they said it's okay as long as it doesn't hurt.

I'm wondering whether it's better to do it as a preventive measure or to do it only if symptoms like chills appear.