There are numerous ways to minimize tooth decay. The thing is,
as compared to fluoridation, other methods require a base of
education about caries and its causes, and a set of practices,
whatever those are, to be implemented across ALL social strata,
ALL ages - especially very young children, who are the least
likely to have that base of education in place, and ALL income
levels to be truly effective.

Many European countries do probably have the education and
practices in place that help to minimize caries that don't
involve fluoridating their water.

Free and readily available dental care for babies and elementary age children and a minimum of sugary foods in their diets would be the desired standard.

Fluoridation of water is actually a step down from that ideal but it
is less expensive and it is universal for the entire community.