What's the Point of the UK 2021 Census?

Some countries carry out a census of their population, so they can use the imformation to track historical trends. Governments (and others) may also use the information in planning and policy-making. The cenus material is also useful to people tracing family lineages. Most of the UK (minus Scotland, who will get theirs in 2022) will complete the 10-year census this month (March 21st). A census is not a cheap exercise. I can't help agreeing with Danny Dorling (Oxford University), the 2021 census risks being "a snapshot of unrepresentative times, an image of pandemic Britain where young adults have temporarily moved in with their parents" (https://www.theguardian.com/uk-news/2021/mar/14/danny-dorling-emergency-census-2026-true-state-uk). Dorling notes the current census, will give the impression that few people in the UK are rough sleepers. This is a temporary consequence of the, soon-to-be-defunct 'All In' campaign. The campaign aimed to remove rough sleepers into accommodation, to cut down Covid-19 transmission. Dorling also suggests there may be hundreds of thousands of people, wanting to permanently travel back to mainland Europe. Travel bans currently make this impossible. One might add, there could also be young people (lacking the substantial finances for quarantine hotels), hoping to travel back 'home' in the opposite direction. Dorling also notes the 2021 census will count 'furloughed' people as 'employed'. This is even though such people might never return to work. He suggests an 'emergency census' in 2026, would paint a truer picture of the UK. It might enable us to track whether plans to 'level up' the economy, to become less London-focused are working. Given, however, the many profound changes that are occurring (the pandemic, Brexit, the climate emergency etc), it's difficult to call a good time for a census.