Ha no the issue with your idea is that the 20-29 represents about 20% of the new cases right now (and I think about 10% younger than 20), so that still leaves 70% of an older population getting infected, and dying at a much higher rate. FYI ages 0 to 29 account for about 1% of total deaths. So to your analogy, would malaria keep going if you killed off 20% of mosquitos?
Just the bad 20%.
But just to rewind this - remember you're defending prisoners & homeless being vaccinated before the children & young adults, That's where this thread started. I presume the reason this is because prisoners & homeless are transmission vectors - but that's a guess. I would argue that the 15-30 year old demographic represents a higher percentage of overall transmission than homeless & prisoners.