Let them mate.
When each airline starts introducing no fly rules without a vaccine, or countries have vaccine passports that include coronavirus then there will be a few more lining up in the queue.
We‘ve been to countries that insist on Hep A&B, yellow fever, typhoid and even dengue fever. Have taken malaria and altitude sickness pills, but we still go.
They’ll just add coronavirus to the list of required injections for travel.
i have travelled quite a bit and have never encountered a border force that requires proof of vaccination. I know some countries get a bit iffy (and some do require certificates) if your coming from a country with high risk of yellow fever, mainly African nations.