I strongly disagree that these are big problems in practice. There are macros you can use to make newtypes more ergonomic to use and reduce boilerplate, etc. Th

I strongly disagree that these are big problems in practice. There are macros you can use to make newtypes more ergonomic to use and reduce boilerplate, etc. The advantage it gives is forced adherence to many implicit assumptions of library authors, which means that it's a lot easier (read: preventing subtle bugs) to compose different libraries. Meanwhile, allowing it might split and completely break the ecosystem.