Decently typed, fast (immensely faster then python), the languages are based on a concise and sound theory and most of newly added features are just sugar over

Decently typed, fast (immensely faster then python), the languages are based on a concise and sound theory and most of newly added features are just sugar over this concepts (like objects and polymorphic variants are just a products of subtyping feature in ocaml), unlike python, where features are monkey patches.