Is there a feature to allow only the host to view attendee cameras?

I am trying to find a video conferencing software that follows the specification of letting the teacher view the students’ faces at all times, but the students will not be allowed to see each other. Would Jitsi be able to help me with this?

no. It could be possible to build (as in: develop) something like that using libjitso, but I have not seen such a project. Maybe take a look at bigbluebutton (I don’t know the project).

this is not possible, however what you can do is when teacher creating room override the channelLastN to -1, this will allow teacher to see everyone and set the global channelLastN to 1 so students can only see 1 video whether it is the teacher or 1 of the participants. btw channelLastN is a flag in the config file that tells videobridge, maximum how many videos to should be rendered.