You phrased it rather well -- "increased constraints will retard the ability to make breaking changes". You are adding a second layer of abstraction that brings very little generalization, but still doubles the mental load; there's no way it doesn't significant put additional pressure when making breaking changes. The natural reaction is that there will be less such breaking changes and interfaces will ossify. One can even argue this is what has already happened here.
In addition, depending on the skill of the "binding writer", the second set of interfaces may simply be actually easier to use (and generally true, since the rust bindings are actually designed instead of evolved organically). This is yet another mental barrier. There may not even be a point to evolving one interface, or the other. Which just further contributes to splitting the project into two worlds.
In addition, depending on the skill of the "binding writer", the second set of interfaces may simply be actually easier to use (and generally true, since the rust bindings are actually designed instead of evolved organically). This is yet another mental barrier. There may not even be a point to evolving one interface, or the other. Which just further contributes to splitting the project into two worlds.