Thinking of "implicits" as one single feature can be extremely confusing. OP is talking about "implicit conversions", which transform values from one type to another automatically just by being in scope.

Cats imports bring in "implicit classes", which are a way to extend existing types with new methods, in a way that works even with parametric types in a type-safe way. That's the way to get ad-hoc polymorphism (aka typeclasses) in Scala.