What makes a good hobby is something that has a cheap barrier to entry, easy to understand, expandable in complexity and use, and is a swiss army knife in that it can solve a multitude of problems. That is what arduino is.
Brand new to arduino and don’t know how to light an LED? You can do that with arduino.
Want to make a garden manager project? Arduino
Making a drone? Arduino–Did it myself
Want to save money by making your own home security system with no subscription fees? Arduino. How many times do I have to say it!!!
So sure there’s a lot you CAN do. But HOW do you do it?