Vietnam has successfully used lockdowns at least three times; up until the last month or so life was normal for the country while the rest of the world was getting slammed and hitting ICU capacity. This last time they refused to lockdown as soon as the infected was identified and this is the result.
So, no.. nothing was inevitable and still isn't. That is about to change because nobody is coordinating regarding taking the needed action on a global scale. Whatever variant escapes the current crop of vaccines is going to be the point of no return.