Object.create, any from of delegation or inheritence, including ES6 classes, and
Specifically, Crockford recommends defining new object types by using a constructor function that creates and returns a new object, and that uses closure to create private variables and so on. The obvious issue with this is that every instance has each of its methods bound directly to the instance; there's no delegation, and that's memory hungry. Crockford claims that this is a non-issue, because memory is so cheap. I found that pretty unconvincing.
Obviously, if you are creating a very large number of instances of anything, you'd use delegation as an obvious optimisation, but we're normally talking about relatively small numbers, so for that case, can we just forget the costs?
What are the runtime costs of following Crockford's advice, specifically regarding avoiding delegation? On the kinds of consumer devices that typically run web browsers, are the costs generally minor?