> e.g. files that don't exist, database rows that don't exist, etc. [...] The workaround is defensive coding, check if the file exists first, check if the row exists?

Ugh NO. Please don't. You should never "check if the file exists first". It can stop existing between your check and your later attempt at opening the file (the same with database rows). That can even lead to security issues. The name for that kind of programming mistake, as a vulnerability class, is TOCTOU (time-of-check to time-of-use).

The correct way is always to try to do the operation in a single step, and handle the "does not exist" error return, be it a traditional error return (negative result with errno as ENOENT), a sum type (either the result or an error), or an exception.

Totally agreed, but as the previous poster wrote:

an exception is meant for EXCEPTIONAL behavior.

So it may be that the file access throws an exception but generally, I wouldn't agree.