I use one daily to paste the date into meeting notes in Capacities and to name files, super handy.

I use AHK a lot at work, and my favourite is a macro that prints the date and my initials. I'm an admin and I use that thing dozens or hundreds of times a day when editing code, configs and notes.

Eg: # Changed in line with CVEnnnn - 20240713DD

This is not exactly an answer to your question, but I thought I would share anyway.

I use Obsidian for all sorts of PC work, and there are a multitude of plugins and scripts to automate and organise all sorts of tasks. I have no need for any scripts outside of this program.

https://obsidian.md/

Edit: let me know if you are interested and want some tips. There are a million tutorials and articles out there too.

I use FireMonkey on firefox. Seems to work better than Stylus/Violentmonkey for me but there's some compatibility issues with certain scripts.

I used autohotkey on an old work laptop at a previous job, as it didn't have any media keys. Made ctrl+arrow keys into play/pause, skip, rewind, so that I could quickly pause spotify when calls came in

Not sure if it fits your question, but here is a little tool I use all the time at work.
We have a radio playing, and sometimes I want to know what song is it.
I made a shortcut in Emacs to go to the radio website, find the "currently playing" title, and print it on the screen as well as saving the date/time I did the request into a "history" file for later reference.

I used to use ControllerMate until it was abandoned. Imagine AutoHotkey but for mac, and with very advanced block programming.

Still haven't found anything like it since.

I use a few of them. There's one to bring back YouTube dislikes, one to translate Lemmy links to my home instance, and another (self written) one to automatically change the YouTube share button to copy which copies the link in s single click.

There are a few more, but these are the most useful ones to me, I guess. I use ViolentMonkey as my script manager.