I was not very clear about it, but I was discussing regular semester work, as opposed to final/midterm exams. Think courses that are strongly grounded in theory but need the students to experience the coursework, like Discrete Mathematics or Linear Programming.
"Oral presentations" in my case meant presenting a homework solution to the TA in person, in front of the class, and the TA accepting this solution live (or not).
At least at my university, the responsibility for homework structure and homework sheets lies fully on the lecturer, and the TAs are tasked with grading the homework/projects and leading the exercise sessions.
Oral exams are great if they can be done at scale, and I do use them. Some other teachers (as well as the administration) prefer written exams, as there is a clear proof of work that can be analyzed if grades are disputed.