I studied for a popular degree at one of the largest universities in Germany. I never had a course be taught by multiple professors. If a course had many attendants, the room just got bigger.
But that's just my personal experience. I don't know if it's different at other large universities.
In smaller countries like Germany increasing the class size makes sense but countries like the US, it just doesn't scale. Just to give a better sense, my quick google-fu (so take it with a grain of salt) shows Germany having 2.8M people actively enrolled in college vs the US with 18.1M.
6x the amount of students, but also 6x the amount of universities, so each individual university has about the same count. At least that's what I assume; unless the USA have fewer universities for some reason?
Ironically enough, our lecture halls were simply not big enough. The space capped out at around 300-600 people and for popular topics such as programming 101 every semester would easily have 1500+ enrolled.
The difference is that in Europe, you apply to take a specific subject at university, like Computer Science, and there are only so many spots available so that effectively caps the class sizes. You don't have a bunch of other people taking the class that are not working on that specific degree.
This is also the case in the US. The majority of college courses are limited to people within a given major and can't be taken by outside majors with limited exceptions.
But that's just my personal experience. I don't know if it's different at other large universities.