Ironically we need to accept the converse.
We need exposure to viruses to a certain degree. Why? Because we don't get immunity from living in sealed bubbles. We get immunity from fighting viruses. Research suggests that exposure often gives us partial protection from other viruses that we have not yet had.
Even with vaccines, what they found was the vaccine reduced the severity of the illness but did not stop it. People who were vaccinated and then caught covid had much higher levels of immunity than those who were only vaccinated. This helps protect them for longer against the most severe aspects of covid. Each subsequent wave is getting smaller in where it peaks contrary to what the media noise seems to suggest.
China which hasn't been exposed to covid and has vaccines which are less effective is caught in a trap of lockdown because its population is much more vulnerable to covid at this point.
Children aren't at particular risk of covid but we know that their immune systems have to be exposed to various things to protect them later in life. There seems to be an issue with a small number of children from lockdowns: they weren't exposed to normal viruses when they were very small as expected. That's had a knock on effect where they believe a number have suffered hepatitis because of this lack of exposure. The research is still ongoing but shouldn't be ignored.
The lesson we learn from the pandemic is that lockdowns are necessary initially, but are also harmful. They have to be short and used sparingly alongside other measures until we develop other ways to manage a pandemic. We then have to gradually reduce protective measures because the closure of society and even restricting the spread of common viruses is detrimental to us. There are some people who are particularly vulnerable who need protection for longer but indefinite protection is also not useful for them in the long term either in most cases. If they are so frail that they won't survive a virus then they probably haven't got long left and you need to consider quality of life. Is being isolated a good thing.
Where there is an exception is people who are temporarily immunocompromised. There is a legitimate reason to protect them but the onus has to be on them isolating not the other way round due to the need for exposure.
This paradox over exposure to a 'healthy amount of virus' is a hard one to get your head around and difficult to balance but it does exist and is as important as vaccines. It's poorly understood so hopefully the pandemic will give us some data we can learn from.
This isnt advocating for a 'let it rip' strategy. It's realising timing is crucial and we need to do better in future to get that timing better to allow us to bridge the gap between the emergence of a pandemic and the development, manufacture and distribution of vaccines and the knowledge of how to treat people more effectively to save the most lives.
We also need to realise that some countries are always going to be more at risk and less able to isolate quickly because of how they are connected to the world. The uk is not NZ. We can never adopt the same strategy because we have very different factors to consider. We also have to be aware that greater inequality and lower numbers of health care staff will also leave a country more vulnerable.
There is no perfect solution. People will die in pandemics. We can work to reduce this, but lockdowns do not stop this - we are seeing the knock on effects now with people dying prematurely because treatment for other things have been so delayed.
Its deeply complex and I do wish the 'we need another lockdown' crowd would remove their heads from their own backsides to see that.