The author is assuming that everyone will proactively start taking this drug. But I don't understand why? If Jerry is not obese, why would Jerry randomly start taking an anti-obesity drug?
If Jerry is a body builder he can get to whatever body fat % he wants.
If Jerry wants to save money or doesn't want to wake up early hungry he can do that too.
If Jerry has religious beliefs about impulses coming from shaitan, he can get rid of them.
Besides, 75% of Americans are overweight/obese that's pretty much everyone.
The current retail cost in Canada is ~$160 USD per syringe for Ozempic.
That's $277-$425 in USD
Perhaps in non-US locations it will be that cheap for sure.