NODE-3976 Description
https://github.com/mongodb/node-mongodb-native/blob/a7a3b99645ec76e4d653537b79263f00b3587e87/src/cursor/abstract_cursor.ts#L630 contains:

const doc = cursor[kDocuments].shift();

In V8, Array.prototype.shift() potentially copies the entirety of the array forward by one element, leading to bad performance for large batch sizes (which we tried using as part of investigating COMPASS-5455 – see attached CPU profile which points to unreasonably much time being spent in nextDocument). Specifically, fetching documents happens in O(nDocuments · batchSize) rather than the expectable O(nDocuments).

If this is adjusted to perform plain array accesses instead of .shift() calls, performance is as expected.