Well, suppose a learning outcome of your course is "Be able to identify a bacteria on a microscope slide" or "Be able to recognise a church with a steeple on a map"
If that is a learning outcome, then a question like drag-and-drop markers is ideal to assess it.
However, it is fundamentally a visual task, so it is never going to be accessible to a blind user.
So, we have to ask what we mean by these question types being accessible.
They are in many ways as accessible as possible. For example, they do not require the use o a mouse, or touch-screen. They can all be done using only keyboard. That is one ADA requirement.
There is a known problem with drag-and-drop into text. The labels are not as good as the could probably be, so it is not as easy to complete these questions while using a screen reader as perhaps it could be. However, Moodle's existing Cloze question type suffers the same problem, and I have never been able to work out a good solution. Suggestions welcome.