This is false. We've eradicated SARS-CoV-1, for example. The last case was in 2004. And New Zealand, Australia, and Taiwan outright eliminated COVID community spread domestically (Australia did it twice!), proving it is possible.
Well no thank you, I'm not an Australian or American but I want my citizens to be allowed to turn home.
Saving your population from each covid death is perfect excuse for fascism, Trump should have been used it to build 3 walls by the look of how people are willing to accept this position.
The case numbers coming out of Israel show their (still ongoing) vaccination effort is on the precipice of eliminating it locally. So it seems incredibly reasonable it will be eliminated, at least from the developed world. From that point any reintroduction of the virus is unlikely to gain a foothold.
As I said, it can't get a foothold. If vaccinations are enough to keep the r0 below 1, which seems to be the case, it doesn't really matter how many infected people enter because it will fizzle out again. Vaccines are also likely to be mandatory for anyone traveling.