"Without better safety measures schools will be closed within weeks. I don’t understand why parents aren’t screaming out for schools to open in a way that will mean they stay open!"
Some of us are! (See other threads on 'are you sending your child to school immediately' etc).
I get the impression that for some people it just hasn't dawned yet quite how things will work. And for many others, they simply do not have any choice in getting back to work, so they're kind of blocking out any uncertainties about the safety, because there's nothing they can do about it, so it's not something you want to think about.
I'm truly sorry OP for the situation as it stands at the moment. I am worried enough about my own (secondary) kids, and also the staff - but can only imagine how scary it must be as a staff member having what basically amounts to a potentially unsafe working environment with nowhere near enough support. Hopefully you will be fine and not catch anything, but you should have more reassurance than just hope.
I don't know what to suggest, apart from encouraging everyone who's concerned to write to their MPs. There doesn't seem to be an easy solution to this because of logistics and because there's not been enough creative thinking in how to use other buildings, for example, to reduce the risk, but I do hope that as the time comes closer, more parents will stand with teachers in calling for better safety.
I really want my kids to get back to some kind of normality (like everyone does), but it's just not going to happen by pretending there's no risk. We wouldn't send office employees back into a hugely crowded office of 30+, sitting all day with bubbles of 120-300 with only a few toilets. I don't see why this is so different for schools.