Templates are the C++ implementation of "generics". Their utility extends far beyond lambdas-as-callables. The entire STL library is built using the Template feature of C++. Templates are far more important than the ability to do "true" object-oriented programming using other features, in my opinion.

For a more concrete example that doesn't rely on the "authority" of an externally developed template library, consider that templates are also useful for static/compile-time polymorphism (see: Curiously Recurring Template Pattern).

My understanding is that auto can serve some of the role of templates, but that has no particular tie to lambdas that I can see.