I think the gap is widening - judging from my son’s school, scouts group and friend’s kid’s schools. This is primary only, no idea about secondary.
Most private schools still have daily online lessons and extend the curriculum. Kids will be more or less where they are expected to be end of the year.
All state schools I know of (!!, that is 5 or 6) have send some worksheets home, but don’t do anything new.
My work colleagues (i work in an R&d organisation, so most parents are highly educated) make sure their kids do the worksheets, read regularly, do spellings, time tables etc. so they will at least comsolidate whta they know.
My son’s scouts group is from a less affluent area with most parents not valuing education particularly. During their last (zoom) meeting, it was clear that most kids treated the last 6 weeks like an extended holiday, with no reading, maths etc done (and certainly no worksheets). If this continues until September, they will have spend 5.5 months out of education. the primary school most of the, goes to already has results way below national average - the outcomes are going to be a disaster for already disadvantaged children.