Every chance to breed is a chance to mutate. This isn't a binary factor its a continuum. 1% of the population is likely insufficient breeding ground and the virus population would collapse exponentially. 70% vaccinated large in contiguous regions may be sufficient to keep the pandemic going continuously if they successive variants emerge that are sufficiently effective at evading existing immunity.

1 person has no meaningful effect but collectively their actions are capable of doing great harm to the rest of us even if we all collectively act in our own best interests by getting vaccinated and participating in other public health measures.

If your freedom to act irrationally allows you to cause my untimely death I don't understand how my inability to go on living wouldn't represent a net decrease in freedom vs forcing you to vaccinate.

If you look at the break down of anti vaxxer sentiment only 9% are dead set against vaccination under any circumstances. These people's perception of their freedom isn't worth hurting everyone.