I use it for lots of things. I'm not a coder, so I can't make my own apps from scratch. With Tasker I can make my own apps. I've made tons of them.
I still have a Reddit account because there are some core subs that haven't migrated, but I don't have to official app installed. I use Tasker to check Reddit and notify me of posts.
My memory is horrible and my schedule is varied every day, so I can't set alarms for certain times. I made an app where I can say something to my watch and it will remind me depending on my location. For example, I can remind myself to get paper towels on my way home from work. When I leave work, it will send a reminder to my watch.
I use it for call screening. I only let calls from my contacts ring. It sends all other calls to voicemail.
I use it to run scripts in Termux.
I have a routine that will tell me why an app was closed.
I have it POST things to the timeline on my watch with JSON.
I have it reassign functions to my phone's buttons. I made an app that turns on the flashlight when I shake the phone.
I have it put the battery level of my Bluetooth devices in my notification bar and on my watchface.
I have it gather weather and notify me conditions and severe weather alerts.
I could go on and on, but you get the idea. You can do just about anything with it.
How did you do that? I'd love to set something like that up. I keep seeing Matrix mentioned everywhere, but I haven't looked into it to see exactly what it is.