Those terrible 'low aspiration' parents probably have the evidence on their side you know.
There is loads of evidence to show that being from a middle class household in itself has a huge effect on educational outcomes way above anything a school can do. So you don't need to worry 
Similarly there is no evidence at all of benefit from homework in primary school. Schools set it to mollify people like you.
Nursery, reception and much of Y1 is about learning through play. If you talk to your child, read with your child, go for a walk and look at what you find, bake and weigh out ingredients, play board games, draw, do crafts then you are educating them. You don't need a worksheet.
I have Scandinavian friends both with science PhDs who appear not to have been held up by not attending formal school until age 7. Yes they went to kindergarten but they never did phonics. I bet you didn't even go to school until you were at least 5. I didn't. School starting age has crept up and up basically for childcare reasons.
In my university town there is a very mobile population of children from all around the world and many start school late by UK standards and not speaking English. By KS2 their results are usually the best in school.
My nephew was adopted. He was neglected by his birth parents and started school half way through Y1 with no ability to read or write. In addition he was coming to terms with his adoption and yet by the end of the year he had almost caught up and by the following year you cannot tell the difference. Kids are able to catch up
I personally doubt that this lockdown will have much effect at all on the educational attainment of little kids.
The ones who can't catch up, the ones who will actually be falling behind are those whose parents don't interact with them at all, neglect their kids, were badly parented themselves, out of it on drugs and alcohol, endure domestic abuse. Maybe your school is putting in a lot of effort with those children? You wouldn't know would you?
But you do you
If you think the school provision is poor then contact the head and ask for more. You don't need all the other parents to agree with you.