One of the things I've come to enjoy about becoming a more senior engineer is how the interview flow has changed over time. Now that I've interviewed lots of people myself, I understand the person on the other side of the desk a lot better and I feel it's a far more balanced relationship.

The issues that candidate employers are concerned about are (should be) more along higher level constructs such as ensuring quality or how to decide on a new technology or platform. What's a really interesting bug you found -- where really interesting probably means it was a system level issue, not just some bad code.

The interview becomes a detailed discussion between peers who are each trying to understand if they want to work with the other.

If someone started out with leetcode crap I'd probably react exactly as you did.