I disagree that you'll find "many red flags for any job"

I've interviewed at dozens of companies, received and accepted or rejected at least 20 job offers in my life, and rarely encountered true red flags. This is very different than saying it's a perfect 10/10, all life is about tradeoffs. What GP is saying is that "there are things that are not worth any tradeoff, and you'll know them by ... ", which is good advice, esp for young people, who might be willing to make uncomfortable personal sacrifices to obtain a job.

We may be there someday, but we're not there yet.