The new dict implementation was introduced in 3.5 (with forced order randomization, which was removed in 3.6) because it is faster and uses less memory than the previous non-ordered dict. Ordering is merely a nice byproduct. So you're not paying any penalty.

OrderedDict is fundamentally different because it is designed to allow inserting/removing keys in the middle of the ordering in O(1) time. It does not use the new dict under the hood, or vice-versa.

Actually, 3.7 are not always ordered. If you delete a key, order is not guaranteed anymore. For performance reasons.

Are you sure about that? I thought they considered that but decided to just make them always ordered in the end.

Keeping the dict ordered is actually faster. There’s a link to a YouTube talk a little upthread that discusses the algorithms used. It’s really interesting.