Good engineering has always been about minimizing the amount of effort it takes for someone to understand and modify your code. This is the motivation for good abstractions & interfaces, consistent design principles, single-responsibility methods without side-effects, and all of the things we consider "clean code".

These are more important than ever, because we don't have the crutch of "Teammate x wrote this and they are intimately familiar with it" which previously let us paper over bad abstractions and messy code.

This is felt more viscerally today because some people (especially at smaller/newer companies) have never had to work this way, and because AI gives us more opportunity to ignore it

Like it or not, the most important part of our jobs is now reviewing code, not writing it. And "shelfed" ideas will now look like unmerged PRs instead of unwritten code