How much bandwidth does everyone have? (short answer: Nope.) You probably want to use Zoom.
Zoom receives video streams from each user and then combines them into one video stream that gets sent back to each recipient. This cuts down on bandwidth but increases server processing. It also means that the room size is limited to the server’s capacity; more people doesn’t increase the bandwidth requirements for any recipient.
Jitsi is strictly a video relay system. If there are only two people, then you talk directly (no relaying needed). This means that 1-1 communications are encrypted and even the server can’t intercept it.
But if there are 3+ attendees, then the video streams are relayed through the Jitsi server to everyone. This means that there are very few resources necessary on the server (CPU and RAM), but there is more bandwidth to each recipient and the amount of data increases with each conference attendee. If one person transmits 2Mbps of video, then 8 people consumes 16Mbps. This may not sound like much if you have a gigabit connection, but if you’re on a smartphone in the United States, then 6 people will probably max out your bandwidth. (Don’t use Jitsi at home if someone else is streaming Netflix or some other video service. You won’t have the bandwidth for both.)
There is also the impact to the client’s resources. 1-1 video requires the client to decode and display one video stream. A room with 8 other people means your client must decode 8 concurrent video streams. More than 6 people might be too much for an older smartphone. (Unlike Zoom, where the client only receives one video stream that contains everyone already it.)