A few weeks before this year's pandemic started affecting the US, I started live-streaming on my YouTube channel.
In the past, I've helped run live streams for various events, from liturgies in a cathedral to youth events in a stadium. (I even wrote a blog post on the topic a few weeks ago.)
For larger events, there was usually a team of camera operators. We also had remote control 'PTZ' cameras, and dedicated streaming hardware like a Tricaster.
For my own livestreams, I had a very limited budget, and only one person (me) to operate the camera, produce the live stream, and be the content on the live stream!