Don't want to dismiss this idea outright but I think there need to be stronger use cases. Your first example makes me wonder why you're comparing those two arrays to begin with. Your second can be solved using algebraic data types or at a minimum can use what's stated here Adding a polymorphic Equatable? - #2 by gwendal.roue
Explicitly, your JSON example can be solved by relying instead on algebraic data types like many open source JSON libraries already offer. This blog post looks like it gives an example Parsing fields in Codable structs that can be of any JSON type | by Sergio Schechtman Sette | Grand Parade | Medium
Edit for clarity: Conforming enum JSONValue: Equality from that blog example should work since all associated values are Equatable.