Now, it could be that the employer is desirable because they provide a lot of perks that you don't really care about, in which case it's perfectly legit to eschew those perks and interview elsewhere. But oftentimes it's because they provide a bunch of tangible benefits that you do care about. Interesting work. Lots of money. Professional reputation that you can then use to increase your desirability to other employers.
It's usually a good career move to take a job at a place where you have a weak negotiating standpoint, work like hell to learn all the skills you can there, and then use professional reputation gained there to increase your negotiating position with other employers. That requires taking a "one-down" position sometimes and hoping that you get lucky and they like you.
Or, as some folks here are fond of saying, "If you're the smartest person in the room, it's time to find a new room."
Given two options, one out of my comfort zone and one in my comfort zone, I chose to be comfortable.
I realized that the value I add is not being able to complete tasks. The true value I add comes in looking beyond the task and figuring out how to address larger problems.
I've noticed in the past that when I continually don't know what I'm doing, I miss out on opportunities to really add value. While I'm able to figure stuff out and get the assigned task done, at best I come across as competent.
It was a great choice. There are still ample opportunities to learn. At the same time, I feel like I have time and mental capacity (freed up by not continually playing catch up with the team) to find and explore new ideas and improvement.
So when people say "Don't be the smartest person in the room" I would say it is also important to not put yourself in a situation you can barely handle. Having some breathing room will make you better at your job and make you far less stressed out.
So, if you ever find yourself in an interview about to go the wrong way, ask.
Look at it this way: Most of the people interviewing you are other programmers – the exact opposite of skilled interviewers. Predicting the day-to-day reality of working with them based on their default interviewing style is just as unreliable as them judging you based on your performance at solving silly brain teasers under stress.
Despite how screwed up this all is, most people are going to end up in many interviews throughout their lives, probably on both sides of the table. So it's best to realize up front that the situation is screwed up but changeable so that when you end up in an interview you'll know to ask for changes.
Obviously this is predicated on the dev job market being as good as it is, but still. I can just go elsewhere.