I haven't used WADL, but WSDL stands for Web Services Definition Language and is an amazing way to define endpoints and messages with type safety. From these you can generate bindings for pretty much any language or protocol that has a generator (and there are plenty, but probably not for the cool kids^TM 'golang' and 'rust').
One of the reasons it fell out of use is XML is verbose and typesafety is not cool anymore.
There is a couple for go and at least one for rust, although I don't know how well it fares. It shines more with languages which allow first-class runtime reflection and code loading, but you only care if dealing with runtime-configured services. Also WSDL 2.0 supports REST.
I would not say fell out of use, most enterprise-grade apis, old or new, will have one -- think bank/government/big corp. GraphQL is not there yet - as other commenters pointed out the tooling is not good enough outside JS world, security is complicated on the service side, and the protocol is just to young - the official release is two years ago, so it may start appearing just around now.
This is rapidly reversing as the javascript ecosystem has increasingly adopted typescript in the last two years. I, for one, refuse to start a new front end without it, and the only other js dev I've spoken with recently who disagreed had never actually used typescript and didn't want to "write a bunch of interfaces like java".
One of the reasons it fell out of use is XML is verbose and typesafety is not cool anymore.