Haven't read the full thread yet, but I agree with you, OP.
We teachers always bemoan the fact that the curriculum as it stands is not helpful to students in later life and doesn't prepare them adequately for adulthood. So now we have a golden, once-in-a-lifetime opportunity to change this - and yet we are trying to still force this unsuitable academic curriculum onto kids and parents.
I'd be all in favour of ditching this and setting relevant work.
English - read. Anything, but read every day. My teen has gone off curriculum and devoured The Hunger Games and various other teen books since the lockdown began. There are plenty of ebooks of you don't have physical versions. Or read news articles, cooking instructions, adverts, the sodding leaflets coming through your letterbox.
Also, write. Write a blog, write a diary, write instructions to achieve in your favourite video game, write to your MP. It doesn't matter, but write.
Maths - now is the time to learn about percentages, mortgages, interest rates. Plan a new layout for your room by measuring its size and the size of your furniture. Work out your shopping bill, work out whether the advertised savings are really such, watch loans adverts and work out how much borrowing £100 would cost you in a year.
Science - if you have a pet, learn about behavioural science - teach them something new, reward them for good behaviour. Observe the life cycle of plants, watch ant trails and birds, do some gardening. Use Corona to your advantage and reserach the disease and the effectiveness of different ways of keeping safe, learn how vaccines work and why their development takes so long. Look at trends in Corona graphs. Research how your body protects itself from disease. Explore the Science of cooking, learn how to heat up/ cool down water/ baby milk/ whatever quickly, try to repair somethings that's broken.
Languages - listen to music in other languages, watch movies/ Youtube with English subtitles, use BBC Bitesize, read food labels in different languages and see whether you can pick out the ingredients without looking at the English version.
History - compare the Spanish 'flu to today - what was similar/ different? Why is there tension between China and the US? Why is the EU struggling and how did it form? Why are there political differences between England/ Scotland/ Wales/ NI?
Geography - look at the spread of CV since the beginning - how did it spread, why? What are the conditions like in those countries? Trace the spread back - plenty of maps out there to help.
Art/ DT - Easter is a brilliant opportunity to make gifts. Learn how to sew, how to alter clothes, how to mend broken items. Plenty of low-cost ways and Youtube for tutorials.
I could go on. I'd be happy to veer off the curriculum and teach stuff that is relevant. I'd be happy to set work, point to useful resources. Just before the schools closed I had to sew a piece of clothing back together for a 16-year-old because theirs split, they couldn't afford new and couldn't mend it themselves. What if they could learn it now? We'd even get more engagement.