For example - I wrote a script that automatically rsyncs a bunch of folders I care about to one external HD, and then replicates the backup to a different external HD for backup purposes.

That sort of thing that would require you to run a bunch of commands and that you have to do from time to time. Automating it to a single script is cool.

I have a friend that wrote a bot to track the prices of stuff that he wants to buy and messages him on Telegram the current price and the min/max since it started running. Another fun little project.