High-level software development is basically building Jenga towers with thousands of (let's be real) mostly not very good parts. Hands up: how many developers think 100% code coverage is the absolute minimum? Then consider that you can reach 100% coverage without ever testing a single corner case. No, not that `if` statement in your code, but rather what happens when this value is zero, when this time zone name is unknown (at any of frontend, backend or database levels), when screen size is unavailable, or any of a bazillion things which can go wrong? Hardware devs have to test these things, and that's why you don't have to reboot every three milliseconds.