I'm pretty sure that the current strategy in the UK is to immunize (as much as possible, partially) younger people with the actual virus, using the vaccination program as a cover: vaccinate in order to have an excuse to open up, and then let it ripe among the (mostly vaccinated) population, hoping that they will get covid but not get too sich and be less likely to get reinfected later. Pursuing herd immunity still... it's a bad bet! But they they (correctly) at least dropped any intention of pursing vaccines that would be useless on younger people.
A reasonable summary, except for the last sentence. There are still indications of extending the UK vaccination program to include at least teenagers, and I suspect the pressure will be there to complete the job once there. A moot point at present - second doses have only reached down to people in their late 30s so far.
And the vaccines are not "useless" in younger people - your argument hinges on Covid being sufficiently harmless to these age groups that the miniscule risk of side effects outweighs it. A dubious argument given the issue of long Covid. I'm not impressed when people keep pushing the "experimental vaccines" line, with the implication that some issue
might appear down the line, while being completely blase about a virus where we
know it causes long term problems.
This was a strategy which the UK was going to have to pursue sooner or later, and while I'm not too happy with the timing - with such a large chunk of the population still unvaccinated - so far, this is more or less going to plan.
https://www.bbc.co.uk/news/health-57942217
While it's still early days, it is worth noting that cases are no longer exponential, even with near universal Delta variant at this point. I'm not going to read too much into a few days decline, but it is a somewhat promising sign that we've at least had a week without further increases. There is of course the issue that there's a lag phase, and we haven't seen the full impact of "Freedom day" yet. That said, I'm not seeing that much of a change in people's behaviour round here. Mask usage is still poor, but that's been true for months.
Anything but zero covid
Have you seen anyone with any expertise in epidemiology arguing this is realistic? Because it's not - and hasn't been since, at the very latest, February 2020. Note that countries you have pointed at to try and support this approach as a possibility, such as Vietnam, are now seeing large numbers of cases. Australia, despite advantages of geography etc. is currently struggling with containment, never mind elimination. Now, postponing widespread infection in these countries is still well worthwhile - but that time should be (and have been) used to prepare. Vaccinate the population, etc. Not to relax and fantasize that Covid would never reach them.