I can vouch for lihaoyi. He is one of the more prolific people in the scala community writing top notch stuff. The best part about most of the stuff be writes is they are extremely ergonomic, even by scala standards. Look at either scala-tags or even better his parsing library. The parsing library is actialy so good you'll feel like finding more problems to solve. Its a breeeze to get started with (even in repl). Scala-tags also is amazing and has spawned other similar projects , one of which is laminar which is currently one of the top scala-js frameworks.

In fact I can probably say this for a lot of his work, anyone learning from him would probably learn a user centric way of library design.