When a new card is created, a seemingly arbitrary deck is preselected, which almost always (if one has enough decks) forces the user to select the appropriate deck.
The current preset criteria is actually mysterious - I though it was the one selected in the previous session, but it isn’t.
It’d be much more user-friendly/efficient, if the deck selected in the tree panel (if selected) was preset instead.
But yes, I also think that most users would expect the same behavior after clicking on “Add” note, so adding “When adding default to current’s card deck” as an option would be great.
Open source and good UX have always been, and will always be, sworn enemies: issue #2341 (“Preference “When adding, default to current deck” has confusing (or maybe buggy) UX”) in the ankitects/anki GitHub repo has been closed as not an issue.