They aren’t http/1 verbs, they are http verbs. They are still used.
As to why you would use rest, well, the alternative is grpc. But grpc isn’t supported directly by front-end. And not all languages and platforms support grpc natively.
Also, rather than rewriting an existing rest api in grpc, you can still benefit from all http2 features (except multiplexing) simply by switching the encoding of messages from xml/json to protobuf.