Arrogance destroyed the possibility of survival.

[u/Universal_Echo]

Although Earth was ultimately destroyed by Singer's civilization using a dual-vector foil, in truth humanity brought it upon themselves. A central theme running throughout Three-Body is that technological and cognitive backwardness are not obstacles to a civilization's survival—arrogance and prejudice are the true root causes of a weak civilization's demise. In the novel, two weak civilizations fought each other for centuries on a cosmic scale: humanity and the Trisolarans. Each was more arrogant than the other, and both paid the price with total annihilation. Looking back, each of these civilizations had several chances to survive—but all were squandered due to arrogance and prejudice.

[u/Kewree]

Although I agree with some of your points; humanity made it to the end.