Honestly if it ever took longer than say a month I reckon we would see alternatives or further development to things like: https://github.com/fr-Pursuit/AsiSupport which in a very basic explanation reroutes calls from scripthookv to the rage plugin hook. There was also this: https://github.com/ivanmeler/OpenVHook which remakes SHV itself.
I think how closed source all the APIs are is super annoying but the only reason alternatives haven't appeared is because it's thankless work and SHV or RPH always eventually come through in the end and release updates.