It's not for me (or you) to decide for others, however :) . I just think there are many more dimensions than raw salary to consider. You could work like a dog for 5 years at a FAANG, make a ton of money, and die just after you retire. It's all weighing the risks and rewards and there isn't a formula for that.
BTW yes, 2-3 months of free time to prep may not be worth it given:
* one will miss/sacrifice other aspects of life
* one may not get the job. Nothing's guaranteed, after all
* the job may not be right even if they get it