The vast majority of online meetings should be audio-only, with cameras turned off.
This is not to say that it isn't ever nice to turn the camera on, especially if you are introducing yourself to a new team or otherwise trying to make yourself the target of everyone's attention. But if you always keep your camera on during work meetings, you will spend a lot of time worrying about whether you are touching your face too much or whether you look sufficiently "engaged", and this will take away from your ability to devote your mental capacity to the task at hand.
This is doubly true if you need to look at code, a document, or anything else while talking to a group of people. If you have your camera on, you have to constantly think about what the other person sees — and that gets awkward when you also need to close-read a page on your screen and want to be able to bring your eyes close to the monitor to make that easier.
On top of all this, there are the usual concerns about how your hair looks that day, and whether or not you got around to shaving, putting on makeup, or otherwise making yourself look "presentable". Let's face it — one of the major benefits of remote work is not having to worry about those things as often as we used to have to.
As mentioned earlier, there are numerous exceptions — I turn my camera on for one-on-ones and interviews, for instance. But for day to day communication, it is usually better to leave it off.