Functional options were exciting when they were first discovered, and they're used in a few popular APIs (e.g. gRPC), but they haven't become as ubiquitous as y

Functional options were exciting when they were first discovered, and they're used in a few popular APIs (e.g. gRPC), but they haven't become as ubiquitous as you'd expect if they were truly superior. My guess is that a struct is the more direct and obvious approach for most people. Functional options also make it awkward to save and reuse a set of options later.