There are problems with this approach. Vaccination exposes all in a finite time. "Natural infection" leaves a reservoir which can continue passing it round for a long, long time. That offers a greater possibility of mutation and reinfection.
If those who want natural infection would all gather together in an infetion hotel (a hastily re-purposed quarantine hotel?), and cross-infect, it is much more arguable.
If you look at origins of the mutations, you will see that aside from the Alpha (UK Variant), other VOC (Variant Of Concern) originated from poor countries with poor virus mitigation and vaccination efforts. In fact, the origin of the original virus came from China, which didn't contain and neither did mitigate the virus adequately despite China's more draconian lockdown and allowed the original wild type to spread globally.
If you look at the United States of America and Canada, US started poorly with virus mitigation but positively with vaccinations and then it lagged, whereas Canada started well with virus mitigation but slowly with vaccinations and then it excels.
What you will see in both our countries is that we never did produce any variant of concern (VOC) did we? We may allow some of our less benign variants (VOI) to mutate and propagate and this is true with our unvaccinated population, but we both didn't produce our own domestic VOC, because of what we did in terms of virus mitigation and vaccination efforts. This is attributed to the great handling of the US CDC and Health Canada. Sadly it seemed that the scapegoating went towards our domestic unvaccinated population both in Canada and the US which were NOT responsible for the variant mutation of other countries. They may be responsible for being infected and spreading the VOC of other countries, but they weren't responsible for allowing VOC to mutate domestically.
Spreading of foreign variants came from both air and sea travel, especially from travellers who went to India and brought back the Delta and Delta Plus variants and travellers who went to Europe or the UK and brought back the UK variant. Travellers are the ones that were mostly vaccinated as well as all having a "NEGATIVE" PCR test as part of the condition of travel and being quarantined. And so why are still infection going on in the planes when theoretically there shouldn't when planes have their own HEPA filter that supposedly filter the virus? In fact, South Korea recently got a traveller returning back from the US fully vaccinated with AstraZeneca and yet still got infected with the Delta Plus variant.
Right now, the 4th wave in many countries are driven by the Delta/PLUS variant. If we completely shutdown air travel and block India, Brazil South America and South Africa would you think we would get the Gamma, Beta, Delta and Lambda variants in both our countries? If we completely shut air travel, completely decimate all airlines and cause them to become bankrupt, the pandemic for both of us perhaps would end in the 1st or 2nd wave. But it didn't, because it is completely unrealistic to shutdown air and sea travel, because we are so deeply intertwined in global travel and our economy is globally connected.
Virus mitigation is no different than mitigation in RATS in our community. If we have 10 homes in our neighbourhood and 10 homes have a rat problem. While you may be able to rid your rat problem by using traps and installing exclusion barriers stopping the rat from other homes entering your home, you couldn't stop the rat population from propagating, because other home owners in 9 other homes may decide to either minimally mitigate or deny the rat problem all together. Eventually, those rats from other homes expand and want to colonize your home again. Whatever exclusion barriers you erected will be broken down again. And that is because, unless all 10 home owner unite together and mitigate the rat problems together, you will continue to have rats because rats have a home to multiply. It's the same way virus works. As long as you allow human hosts to act as virus factories in a country with a leader who deny the virus existence or do little in mitigation, you will continually export new variants to Western countries, because we don't make anything anymore. We import trinkets from South America, Asia, Eastern Europe and globally like many homes in a community. Unless you move all production back to your domestic markets, then variants of concern will always exist even if you have most of your population vaccinated, because eventually a new variant will defeat current vaccines just like a rat gets smarter and not fall for the same traps.
We all live in a global community where all of us has to unite together to mitigate this virus. Otherwise, what we are seeing now is an "Everymen for himself" situation in countries where countries who can afford boosters buy them, like fortifying the exclusion barriers to resist more virus infection. Will this work? Well my experience with RATS is that it doesn't. It takes a community effort to rid all the rats in a community. The same effort must also be duplicated globally with COVID.
