

That’s the historical meaning but it can also mean this (according to Merriam Webster):
3 a: to reduce drastically especially in number
An outbreak of cholera decimated the population.
Kamieniecki’s return comes at a crucial time for a pitching staff that has been decimated by injuries.— Jason Diamos
3 b: to cause great destruction or harm to
A fire decimated the city.
An industry decimated by recession

I thought the same thing right away and it makes the whole thing seem like a dystopian dark comedy. What a nightmare.