The purpose of trace-and-test is to avoid having to lock down.
The purpose of fast, local, brief lockdown is to get trace-and-test back into the lead.
We don’t yet know how well vaccination will work. Vaccinated people can still spread the infection, and can still get ill; this strongly suggests that people who’ve had covid before also can still get ill. Then there’s the long term damage; we can’t possibly be sure that we know all the long term effects, and the ones we’ve already seen aren’t even understood yet. Some viruses cause cancer, eg. human papilloma virus causes warts, but a few years later it can cause cervical cancer. In ten years we could be struggling under an epidemic of cancer caused by SARS-CoV-2, because we let it run riot.
It seems sad that so many people would rather just give in, to a mere virus,the most primitive life form possible. I guess our society is decadent and well on its way to collapse.