That's currently not a realistic scenario AND it's extremely unlikely to happen so I think the end game will be something else.
We're not going to reach 90% vaxx rate unless this mutates into something more like Ebola with a 30% fatality rate or unless the government takes draconian measures, like stopping welfare payments unless recipients take the jab, banning interstate travel, and nationalizing Pfizer/Moderna and taking their patents on the vaccine so the entire world can make it. Politicians... Dems and Republicans... don't have the guts to do that. The sad truth is that both parties care more about being reelected than about people dying.
And a 100% vaxx rate doesn't stop COVID. The vaccinated still get COVID and it still can mutate. The best outcome I can see is that COVID mutates into something highly infectious but extremely mild. The entire world gets it and gets immunity. The worst case is that it evolves into something vaccine resistant and deadly.
Getting back to her point that the end game is vaccinations, I agree that it's the most realistic way to prevent COVID. However, that comes with the a priori assumption that the vaccine will have no long-term effects. That is simply an educated guess at this point. mRNA vaccines show great promise. Maybe they will have no long-term effects.
It comes down to trusting the guess of experts who extrapolate short-term safety into long-term safety.
As an aside, we're told to trust the science when the scientific method says, "Research. Form hypothesis. Test. Observe. etc" We haven't observed long-term results because only 36 subjects have had the Pfizer vaccine for over a year as of this date.
You trust the vaccines. Fine. I hope they are safe. If they prove to be after waiting and observing the results, I'll get the vaccine, too.
Curiously, and I mean that as an observation... not sarcasm, the current vaccination rate is roughly what the best flu vax rates have been in the past. I'm surprised that it has gotten as high as it has.