As far as a hobby, some people just like to get on there and talk to other people or join onto "nets" which is basically an on air meeting where you discuss a topic of interest. The Dallas club has daily nets and a weekend net where they usually do like a book review. It can get kind of nerdy or weird, but sometimes it's fun and interesting. I usually don't talk much myself. And that's all local stuff, VHF/UHF frequency. I have a 22ft antenna in my backyard hooked up to a 60 watt $135 Kenwood VHF radio. At 60 watts, I can hit the Ellis Co repeater in Ennis , TX 25 miles away. That repeater is linked to 2 other repeaters in Ellis Co., so I can pretty much talk to any other users in Ellis Co., probably 1/3 of Johnson Co too.
The useful part for me is the weather, if there's hail or tornadoes, they usually spin up in Ellis Co before they get to my house or business. Gives me some warning, time to prep, hide cars whatever.
And this is separate from HF ham radio that operates on a different frequency and requires a different license, different and more expensive radios and bigger antennas. You can easily drop $1k just getting a basic HF setup running.
I have a little icom 703 10 watt portable HF radio. It has the power of a mouse fart and it still cost me $500. The long wire antenna was $100 and if I move it around, I can receive Mexico, South America, the Caribbean, Alabama, Florida, Louisiana, etc., sometimes, Europe or Africa, but I've never tried to broadcast out on it since I'm not licensed. It's just an interesting toy at this point.