Way overthought. There's 3 things happening: 1. Waiting. We have `sleep` for that, or `at` or `cron` if one wanted a different interface. 2. Accepting seconds in a more user-friendly format. We should make a separate program for that so we can reuse it in other contexts. 3. Notifying. Notify-send is all we need. The -c addition echoes back the output with 2 new words and a newline. No added value. If there's need for another backend like echo one could rather implement --notify-with (notify-send|echo|...) or --json to allow other consumers but at least add the seconds-to-wait information as well. I don't see much added value in that anyway though.

So..

> Some might see the expansion of a single compound command into a nearly 200-line script as a sign of everything wrong with modern software development.

No, just avoid - looking for functionality that noone is asking for (YAGNI) - complecting