Not a virologist but it is my understanding that any virus will only develop vaccine evasive work arounds in an imperfectly vaccinated population. Especially where vaccine only inhibits severe symptoms but not infection. Especially when community infection is high. Especially when those infected don't exhibit the symptoms that qualify for testing and fly under the radar.
These are not sterilising vaccines. If they were there would be no debate and only real anti-Vaxers would refuse the vaccine.
The virus naturally mutates but also mutates when presented with a puzzle. It's an experiential learning process the virus can only go through when it infects someone who is imperfectly vaccinated. Then it can transmit to better infect the unvaccinated. Not the other way around. So imperfect vaccination puts the unvaccinated and young and global population at increased risk.
In these circumstances you could equally argue that ultimately it is selfish on a global level to participate in interventions that are designed to protect the health services, educational services, sectors of the economy etc in the western world in the short term but globally may make things much worse in the longer term.
The narrative has slipped from vaccines only preventing serious illness and death in the elderly and vulnerable as an emergency measure in the absence of effective treatment to vaccination for all adults and vaccination being mandated for all, including under 18s with sanction.
I think the focus on vaccination is making us blind to pertinent questions. How was the delta wave in India 'brought under control' despite the lack of vaccination? Historically, why did the so-called Spanish flu first target the elderly and health care workers but then the young and healthy (not because of vaccination)?
If we don't understand how virus work we can't understand how intervention works.