Often, explaining/teaching has only short term value in terms of the product. The code will outlive the team; I try to factor the knowledge into the code, making the code easy to deal with.

I also spend a lot of time explaining and teaching, as it is necessary, but it's really a stopgap measure. Give it a few years and there's mostly new people.

It was cheaper for me to ask my junior which of two blocks he understood more easily and eliminate the style he didn't grasp immediately throughout the project than it would've been to try to teach him and every programmer that follows him on the project for sure.

Agreed, but if cheap is your goal, you shouldn't be hiring junior devs. The leanest companies I've seen/worked for were all senior people. "No passengers".