Yup, totally hear you. It's totally achievable, but not simple; Haskell has this issue too, for example. There's been a few iterations of the design already. The current approach is to cut scope as much as possible to ship the basics sooner.
It is this lack of non-type template parameters, template templates (ie higher minded types), and variadics that make Rust feel like a step backwards compared to C++. When, Rust gets these, it will remove a a major blocker for me.
