The controversy over inheritance has to do with implementation inheritance, where any method that's defined on a base class can depend on methods that may have

The controversy over inheritance has to do with implementation inheritance, where any method that's defined on a base class can depend on methods that may have been overridden in some derived class, or rely on some non-codified invariants that a derived class might break: this is known as the "fragile base class" problem. By using composition over inheritance, this is not something that can happen by default, because there is no provision for a method call on some "base" method to dispatch on the object's "actual" type, or more broadly to rely on anything but what's defined in the base object itself. You can recover that dispatch-like behavior ("open recursion"), but it's something you have to code yourself and opt into explicitly. This is good for rigor and auditability, as well as just being all-around simpler and easier to understand. Implementation inheritance is too general of a feature, and just not a good abstraction.