The few people I have spoken to in the past year who have also studied viruses in their life have said this has been the wrong way to lockdown and isolate a virus. Lockdown has to mean lockdown either in its entirety for a short while (logistical nightmare) or isolate the old and vulnerable with state funded deliveries to them by the rest of us (cheaper for the economy) whilst the rest of us get on with it, have mild illness and develop herd immunity. If that is correct, ....
Erm, it isn't quite correct. It may misunderstand the meaning of "Herd Immunity".
1) Infections evolve and mutate. This means even when you may have survived one infection they can come back later and have another go, with a different variant.
2) The more people who we let become infected, the longer the infection is around, and the more chances we give it to do (1).
3) Having been infected and recovering doesn't automatically give you life-long total immunity to either the variant you had or to any new variants.
4) Neither previous infection nor vaccination ensure with perfect certainty that you can't get infected again later. Nor does it guarantee you then won't infect others. Even for the variation designed for the variant you were exposed to. Its main effect is to reduce the seriousness of any future infection by giving your immune system a 'head start'. So you may be less unwell (to the point that you don't even notice you are infected) or may then not generate enough infection 'load' to have much chance of infecting others.
The point of vaccination is to reduce deaths and serious illnesses, and reduce the infection rates. This then makes the infection easier to reduce further by other measures and get control of the situation and a state where most people are OK, and infections can be chased down without the NHS crashing and burning.
So: Without effective vaccinations and/or social measures to break the infection chains, "Herd Immunity" is either a myth, or means repeated infections, year after year, each time killing and maiming some people. Stress on NHS workers, etc.
Infections like smallpox were eventually eliminated by 'ring vaccination' which requires being able to find every case and then stop them infecting anyone else. Not by mass vaccination trying to 'catch up'.
Sadly, the common view of "Herd Immunity" seems akin to cows in a field feeling they are "immune" to the farmer sending them to the slaughterhouse because they weren't put on the most recent lorry!
Dose BloJo understand any of this, or even that water is wet? I doubt it. :-/