I think this is unfair to the OP, obviously she/he is stressed about the situation, perhaps offer something a little more constructive.

I appreciate what you're saying, and agree this could be an opportunity for not only OP to grow as a professional and also educate multiple team members...

But in my opinion, OP appears to be asking for a justification to leave the role, not for advice on how to get the most out of their situation.

In order to offer some advice on how to get the most out of their situation, I feel I need to first explain why it's an opportunity in the first place.

In a saturated industry, there will be someone else who would ask "I've found myself in a lead position, in a team of underdeveloped engineers, how can I be more effective in my capacity as a lead?". So why bother converting OPs viewpoint? If they've got into a lead position, they've probably been working a while.

Therefore, it would benefit OP to move to another role they're happier with, and also open up an opportunity for someone else who could better benefit the employer.

Considering that it's almost impossible to get past any whiteboard interview without an understanding of Big O, I think you're being a bit too harsh on OP here. It's literally CS 101.

I don't think I learned much Big O until about my junior year. Maybe some vague mentions sooner.

Looks like you're right. I didn't realize that most student don't get exposed to Big O until their first real algorithms course.