DELETE is for deletion only, this request can't have body, so only what we can do is send id in query. When we want to remove multiple resources we either should send multiple requests (what is slow), or combine multiple ids in query (what is ugly and non-idiomatic).
In your mind, what does URL stand for? It's an acronym.
Do you really expect to get resource data when you send POST or DELETE request? If yes, then web (and REST) is not as perfect as you expect.