@ITonyah
state school trying to work out how to teach 10 lots of 30 children by teams?
Tbf if you can use teams it doesn't matter if you have 10 or 30 children at the end of the line!
Of course the number of pupils makes a difference! A live lesson isn't just the teacher delivering a spiel to the kids while they sit there, rapt. If it was, it would offer absolutely no conceivable advantage over a recorded video lesson. The teacher needs to interact with the pupils and assess how they're progressing. In a classroom you can do a lot by glancing around the room, by a show of hands, by noticing where the pupils are looking and how they are reacting, and by setting them quick tasks that just take a few minutes, and walking round to see how they all get on. On Teams it is much more difficult to do that sort of quick assessment, and nearly impossible to do it effectively for a class of thirty without the pace of the lesson dropping to the point where you lose too many of the pupils.
To chip in on a couple of other points - not all versions of Zoom allow you to change the background. I have it on an old laptop (Windows 10, but limited memory and processor) and it will only work if I have a green screen behind me.
Oh, and my employer (professional office job, not in education) has provided me with a laptop, two monitors, keyboard, mouse, fully adjustable desk chair, printer, shredder and a large box of paper. When I taught, I bought all my own kit. I think one poster suggested teachers should expect to do this because they were a freelancer or similar and that was what they had to do. They seemed to have missed the point that teachers are employees, not small businesses or sole traders.
Employees are supposed to be provided with the equipment they need to do their work. Teachers are certainly not allowed to hold pupils' personal data and interact with pupils' by video on their personal devices. That would be a serious disciplinary offence in any LEA I worked in when I taught.