I agree with Gergely Polonkai and Steven Ventimiglia but I would like to add one small bit; there are lots of "full stack" jobs out there now. Just because they said "don't trust anyone who says they're full stack" or "no one is full stack," doesn't mean you should not apply for these jobs in some circumstances because the term is thrown around loosely. What this means is that if you see a job posting for example which specifies "at least 1 year experience in full stack development." This shouldn't translate into "oh crap well the guys I trust at Hashnode said I'm not fullstack or shouldn't call myself fullstack so I won't apply." But rather
This company says they want a full-stack master but what they really want is someone who is familiar with one group of technologies and can use them to solve problems from CSS to SQL and inbetween.
In other words, many firms now adays aren't looking for a real "fullstack master" when they ask for fullstack devs. They're just looking for people who have done some projects throughout the stack and are comfortable solving problems with it; Someone who can pick up and start chugging with the stack and who has developed good habits with it.