Ham radio can be used as voice chat with friends, but that would be a pretty limited view of it. Here's some things that a Discord Voice Chat cannot do that radio can:
- Chat without internet (e.g. places without cell towers).
- Chat without voice. (digital communications of all kinds; email/text, keyboard-to-keyboard, pictures, etc).
- To build an internet (e.g. building WiFi meshes with extra power [AREDN], AX.25 packet, WinLink).
- Used as a tool during emergencies (see ARES/RACES/CERT).
- Chat completely randomly (it's just one big discord channel, but you can only hear some people).
- Chasing the challenge of unusual radio propagation (earth-moon-earth, meteor bounce, tropospheric ducting, aurora).
- Chasing the challenge of collecting the most point-to-point contacts (contests).
- Chasing the challenge of difficult radio propagation (microwave links).
- Constructing and using radios that you cannot buy off the shelf parts with (usually with those funny microwave guys).
- Higher power versions of things unlicensed folks cannot do (RC toys, Meshtastic/LoraWAN, WiFi, etc).
- Historical preservation (restoring old radios, keeping ship-shore coastal stations running [e.g. Maritime Radio Historical Society]).
- Conducting scientific experiments (HamSCI, and I conducted one listening to the ionosphere during the recent total eclipse).
- Building and controlling satellites (AMSAT).
And there's even more. The way to view ham radio is the government grants you a license to operate on many pieces of radio spectrum so long as you can show your technical ability to not cause harm (interference, safety, and things that will prevent you from blowing up your radio as well as find success in using it). What you do with that spectrum is up to you!
I upgraded my license when my grandfather had to move in with my parents so I coul help him setup a smaller shack and assist in operating the radio with him. He deeply appreciated the family time, and I'm sure your Uncle wouldn't mind spending time with you too.
For whatever it's worth, these web interfaces are great at listening and cost nothing. Ask him to help you operate (finding signals and how to listen to them) using a KiwiSDR online. If you find out he's also having fun, then perhaps look into remote radio station equipment. There's a wide selection of transmitting capable SDRs, like FlexRadio, and DIY solutions (e.g. https://www.remotetx.net/). You can even rent remote operation time with incredibly nice hardware in amazing locations (e.g. https://www.remotehamradio.com/). Perhaps he'll be come interested in another side of ham radio that he hasn't done before either, like working satellite passes. That doesn't take more than one nice, or two very cheap, handheld radios and a small handheld yagi.