Hammerspoon is one of my favorite tools. I especially like the low latency of the system hooks, other tools like Automator or Folder Actions have a couple second delay betweeen the trigger and the action. Hammerspoon is pretty much instant.
On top of that, Hammerspoon is very actively developed and the maintainers are super knowledgeable and responsive.
It is a truly great tool. The caveat is that using Hammerspoon is essentially programming. So it is "only" suitable for technical users like developers.
For the casual Mac user (e. g. product manager or the guy from sales) the visual Sikuli or UI.Vision RPA tools are more suitable for creating automation scripts.
On top of that, Hammerspoon is very actively developed and the maintainers are super knowledgeable and responsive.
I've shared a couple scripts on here before, like Anycomplete (Google autocomplete anywhere): https://news.ycombinator.com/item?id=13065670