Is anyone even seriously claiming that a disease that spreads twice as fast is going to infect twice as many people? As long as the effective R0 of a disease remains greater than 1, it's eventually going to infect the same amount of people — everyone (over the long term). Greater R0 rate just means it spreads faster.
The real concerns about omicron are that: 1) A rapid initial spread will overwhelm the healthcare system and 2) that if its basic R0 rate is sufficiently high, then even after remedial measures are taken, we will still be left with an effective R0 rate above 1 for quite some time.
