I don't understand how you can, on the one hand, be so desperate to get your child back to school but, on the other, refuse to consider any measures.
I also think primaries and secondaries are very different beasts, especially with the size of secondaries, numbers of pupils and risk. I don't think primary school aged children need masks, but a room full of seventeen years old is a different story. There was a documentary on BBC about the Italian hospital at the centre of it all. There was a boy who was 18 with no underlying conditions and he did recover, but was on a ventilator and very ill for a while. Very, very frightening.
Getting children to wash their hands more, wear masks, keep their distance is hard to do when you are a parent, but in a whole classroom I can't see it being easy.
You're right that it's not easy, but I don't think the correct response is to say uh well, don't bother then! I saw another video of a school in France where sinks were installed in the playground. That seems a great idea to me. It just takes money and time!