600k deaths in the US is an accurate count. But, by the time the US really started rolling out the vaccines in January and February there were already 400,000 dead. Now as less people are dying from Covid in the states and as the US get's closer to magic 70% one shot vaccinated number more people are going to reevaluate if they want to get a vaccine at all. Plenty of people from all walks of life that are anti vaccer's and they should be able to chose their own path out of this pandemic.
The problem is that those people not willing to be vaccinated put at risk a lot of people. Remember the protection for fully vaccinated people is around 90%, not 100%, and we don't know if any variant will lower this.
As june 15th in USA:
https://usafacts.org/visualizations/covid-vaccine-tracker-states/
At least 174,674,144 people or 53% of the population have received at least one dose.
Overall, 145,768,367 people or 44% of the population have been fully vaccinated.
With roughly 33% of Americans hesitating or not wanting the vaccination, it's hard to share your optimism to the magic 75%. Even if you lower it to 70%, the road is still long to go. Deaths are on a plateau, not really going down and organizing lottery, giving hotdogs don't do much to convince people on something being still a political issue rather than an health issue. Too many leaders, as Ron de Santis in Florida forbidding mandatory vaccination proof to get access to a cruise ship. I truly hope USA will get to this 75% fully vaccinated but the sooner will be the better and I can't see it in a near future even if this country has a huge production capability.