[1] https://covid19.homeaffairs.gov.au/leaving-australia
(quote from that link: "Australia’s borders are currently closed and international travel from Australia remains strictly controlled" )
Like you, I make money from travel, but difference is being stuck in AU suits me because it's where I have my contacts!
This has been the status quo for dozens and dozens of countries around the world with regards to for example Yellow Fever Vaccination, so it's nothing new at all. Many people just didn't know about it because they never tried to go to those countries before (West Africa is my personal experience)
There are countries that require all arrivals to quarantine regardless of vaccination status. I live in one of them (Taiwan).
The issue with COVID vaccination is that it's still possible to become infected and transmit the virus to others even if you're vaccinated, so requiring vaccination for arrivals is a good way for countries to reduce the risk of arrivals getting seriously ill and burdening their healthcare systems, but it doesn't at all prevent the virus (including possibly new variants) from being introduced into their populations.
The science shows that neutralizing antibody levels wane quickly after COVID vaccination, and with Delta, this appears to be what's causing large numbers of breakthroughs. For example, we had a case here recently where an ostensibly healthy airline pilot in her 40s caught a Delta breakthrough case just 2 months after she received her second Moderna jab.
A single jab of yellow fever vaccine on the other hand provides lifelong protection and we have decades of data showing its efficacy. Also of great importance to note: unlike SARS-CoV-2, yellow fever does not transmit directly from person to person.
I'm just saying they will all require proof of vaccination for covid to be allowed in.
And again, I'm just saying that this doesn't stop the introduction of the virus into the population, which is ostensibly the primary reason for requiring vaccination.
And what constitutes "vaccination"? 2 jabs? 3? 4? How are you going to verify vaccination records when most people are just getting cards that can easily be forged? What about people who have been vaccinated with a vaccine not approved for use in your country?
SARS-CoV-2 is well on its way to becoming endemic. There's likely to be a temporary phase where quarantines and/or proof of vaccination are required but this isn't going to be permanent.