Not that you should’ve gotten downvoted, but to be fair your logic isn’t completely sound. The death rate isn’t the same every year and it’ll definitely not be the same in a hundred or so years. As time goes on more people will die each year because populations get higher and higher for age group. Most people currently dying of old age were born when the population was significantly smaller than it is now

You’re both right. He’s saying how long he think it’ll take for 8 billion people to die based on how many people die per year currently which isn’t 100 years. You’re saying how many people will die in a 100 years.